Actually she can easily poke you while CSing with her Q. She can also CS with her other abilities. Backing lets her easily catch up in CS if she's down a little because she doesn't have to back unless you're poking her out, which you probably aren't because shunpo dodges most of it so easy in many matchups.
If she's poking you with Q, she's in range to be poked back, and your spells do more than hers because she has terrible base damages and ratios. If she shunpos to dodge a skillshot, it has a longer cd than any poke spell you just threw out. She also loses all lane pressure because she can neither commit to all ins or retreat from fights/jungler ganks for the next 12 seconds. During this time she should be zoned from attempting to take any cs by your basic kit, which will easily half health her in one rotation of basic spells regardless of your champion. The only other spell she can cs with is W, which is close enough range that you can easily punish if you're actually paying attention to your minion health and where she'll make the attempt.
If she's Csing with Q, as she should be forced to do, she not only isn't harassing you, but she's actively pushing the lane. It's similar to tristana, she can't kill a minion without pushing the wave, which means she can't freeze. Even if you suck at freezing lane, katarina is forced to give you multiple tries by constantly slightly shoving lane.
"well sure, it's targeted, so are a lot of much better spells"
Such as?
Annie Q, Vlad Q+E, Anivia E, Brand E, Malzahar E, Cass E, Kass Q, Kennen mark infused attack, Leblanc Q+R, Swain Q+E, Viktor Q, Teemo Q.
Katarina's poke damage is capped by being manaless, having resets, being multihit, and having the second mark component. It is outclassed in both damage, utility, and CC by the majority of AP carry ranged targeted spells. Even when accounting for the secondary mark damage, which is completely unsafe to go in and proc, Q still provides less damage than many of the spells mentioned above.
"it has a pretty average if not sub par range for a targeted ability... "
Actually due to its ability to bounce to you off minions it's one of the longest range targeted abilities up there with Dark Wind from Fiddlesticks. Pretty much every (non melee) targeted ability in the game has a low range as far as its initial target goes.
So don't stand next to minions... You simply being out of range of your minions forces kat to decide between harass or cs. She can't do both, not with the lane presence any decent midlaner will put on her. Not to mention the fact that only 60% of it's already minimal damage is going to remain by the time it reaches the end of it's bounces.
Her laning phase isn't actually that bad. Also several other assassins have very similar laning phases. You can't just guarantee your bot lane isn't bad. Also her speed (including ability to get boots faster than any mana champ due not needing to buy mana items) is kinda high. She shunpos to get there faster too and is good at diving, so even if they play a little safe she might get them. The mere fact that they have to play safer due to her being in the game is part of her power, though yes that's a common thing among assassins.
Her laning phase is the worst of all assassins and has only 2 winning matchups. The vast majority are heavily in the other midlaner's favor with a few being close to an even skill matchup. Her speed should be irrelevant if you have a single ward between midlane and botlane or just a slight amount of map awareness. Bot lane playing safe isn't a detriment to your team. While they're playing safe and maybe not capitalizing on all they could or missing more cs, katarina is missing cs, experience, tower damage, map control, and vision control by trying to roam and giving up her position mid. Not to mention this all comes with the possibility of a counter gank, which your team could easily set up if she's following the trend of: push in lane - roam bot lane. Kat's risking a huge amount by roaming, especially when she can't rely on going back to a passive farming lane to catch up.
The key difference is the speed and mobility at which she can get there. VS Syndra or Annie or Xerath your carry can rely on vision over actual walkways to be enough. That's one of the reasons people hate the high mobility many champions have now. High damage champions that can easily and often get over walls create a much higher pressure around the map and increase the amount of vision you need to be safe drastically. Kat's not alone in this for sure but when combined with the rest of her kit it puts her up there with LB and Zed in terms of speed crossing the map over any path and then deleting someone instantly and can still get back out alive.
I understand your point if you're talking about her just flashing over a wall in a jungle teamfight to reach your backline. But if that's the case, your team shouldn't be fighting in enclosed spaces with little vision. That's the optimal scenario for katarina and assassins in general. You also shouldn't get caught stuck in a linear path against a rumble or clump up together against an amumu + malphite + oriana team.
But outside this scenario, I don't see how your team would reasonably be caught out in a lane with no vision on either side while a katarina flanks you. If kat is getting behind your team, you have poor vision control. This doesn't mean warding 100% of the map, this means vision should move with your team. Wards should be preemptively placed in a bubble around your team as it advances or retreats, while keeping in mind that any bush that you're about to ward could have a full team in it if you don't already have vision of them.
It also sounds like you're saying katarina uses ward+shunpo to normally traverse the map. This doesn't happen, not to the extent you're making it sound. She isn't a nidalee or a kassadin traversing the map with a short cd jump. She isn't leblanc or fizz or zed who have other defensive options if they are caught in a bad situation after they jump. She isn't a Lee sin or a reksai who are tanky enough to survive a bad situation after they jump. If katarina uses her shunpo to just jump over walls to roam bot lane, she is giving up a 12 second window where she has very little killing power, and even less living potential if any champion besides the support shows up. Again, I'm not talking about her just ward hopping over walls onto your adc or shunpoing to minions in her own lane to be more mobile. I'm addressing what sounds like you claiming her shunpo allows her to traverse the map and create more pressure when her shunpo's realistic potential is contained pretty close to where her targets are. Shee needs to have shunpo up when she's within range of her targets, her entire kit depends on it. She isn't using it for mobility towards her target nearly as much as most other mobile assassins. Not to mention it's also optimal for her to max it last and also she doesn't build cdr items, so her shunpo is still on a 12 second cd until around level 13.
There's so much wrong with all that where do I begin? Lets see... Melee? Her abilities all have a range, calling her melee is like calling Zed melee, he can kill you easily without ever having to auto attack you so that's just pointless to mention.
What? What does being melee have to do with auto attacking or not? That's like saying syndra isn't ranged because she doesn't really auto attack much when rotating through her spells. Zed and Katarina are both melee, this comes with a disadvantage in lane of needing to CS either with abilities, or by putting yourself in danger and taking free harass. I've explained above how kat CSing with her Q is detrimental to her lane control and how W is just as punishable as auto attacking for CS.
They might out range her but they don't just have true sight on the whole map 24/7 and can't just choose to never be CCed.
You don't need vision to know what you don't have vision of. For some reason the default mind set of a lot of players is "I don't have vision of the whole team, I guess I have no information of those other champions". You might not have vision of someone, but that doesn't mean you don't have any information about their position. You don't know where they are, but you do know where they aren't. If you can't see a katarina farming top lane while there are 4 of her teammates pushing down mid, maybe you can make the assumption that she's probably close by to them, maybe in that top side bush that you don't have warded. The point is you shouldn't be forcing fights when you don't have vision, and you shouldn't be baited into fighting and just blindly hoping that the enemy katarina isn't competent. You need to regain position and vision through map control, you can't just fight back and complain about a katarina capitalizing on improper vision when you were aware you had improper vision.
The CC argument is just stupid. If you're getting CCd and you're low enough or squishy enough to die to a katarina, you're certainly low enough or squishy enough to die to any other assassin, ap carry, or fighter. Does katarina snowball more damage off of that kill than the other mentioned categories? Yes. Does that your team would only have lost against the kat? No, every other category has plenty of ways to exploit a 4v5 even if they aren't as strong as a katarina with resets. And this is balanced by the fact that katarina is even weaker than those other categories of champions until she gets that reset. You can see how that would be frustrating at a higher level of play where stupid little mistakes aren't made as often. People complaining about how overpowered a champion is when they get that first reset, and you're sitting there thinking, "How in the hell is anyone giving her an opening for a single reset?" Shutting down katarina in lane, in roaming, and in teamfights is so simple and flowchart, people just don't take the time to learn how to actually play against her and complain to get her nerfed instead because it's easier than actually growing as a player. (ran out of space continued in next reply)