Because people have zero clue how to build him
In a post I posted a week ago, you ryze mains are now quite literally ryze noobs.
You don't max Q anymore, you max E for starters. Shit, I would argue you max Q last.
AND DON'T BUY FROZEN HEART.
That Item is awful on him post rework. It is outclassed, and is mostly a waste of stats.
Stop building him as a bruiser. Sorry, but having rod as your only AP item is not cutting it anymore.
"What are you talking about, I know how to play ryze stfu"
http://champion.gg/champion/Ryze
His most frequent core build is trash. Look at that.
Maxing Q is bad because all it offers the least out of all of your spells until lategame. E is a better spell if only one target is next to the initial, and W is better per point because the duration and damage go up. (What do you mean max E wtf its a rng spell). No, it's not. That was reworked. E will currently hit the initial target, then bounce to up to 6 targets near the initial. Now, here is where this spell gets REALLY powerful. After hitting the secondary targets, all 6 shots will bounce BACK to the initial target, dealing even more damage per shot. Meaning landing an E on an enemy in a full minion wave will ensure they take at least 250-ish damage from E alone, plus the burst from W.
If you play right, you should easily be able to out sustain and out poke lane opponents whom do not directly counter you.
Maxing Q does not reduce the cooldown, increases the cost, and only gives 100 damage at rank 5, plus .5 mana scaling, compared to his E which gives 5X that amount if you land it in a full minion wave (which is stupid easy in lane).
Ryze is deceptively strong right now, and his only real problem is how bad his passive is until you get 2 points into ult.
You see the passive only lasts 3 seconds, but goes up for 1 second for every point into your ult. You ult also gives cdr, which makes your passive even more effective. The passive is being buffed to last for 6 seconds flat starting at level 1, meaning ryze will actually have a midgame compared to right now, where he HAS to farm until level 11. With this change, he should be able to start making plays at around level 8-9.
Now, laning on him is really easy and safe, you have zero reason to be losing trades if you play them right. You probably won't get any kills, as ryze lacks all in kill pressure early game. Sure, if you go all in at the right time you will send them running, but you will not be getting a kill unless they get greedy or where already low. Start Sapphire, Max E, then W, then Q. Back when you have enough gold for a tear. TP back to lane. Focus on farm. Whenever it is safe to do so, poke. Simply use your W while the enemy is standing in their minion wave, then E them. Watch as half their health bar disappears and they can't do anything about it other than stay away from their minions, meaning they cant farm unless they are ranged.
Now, Ryze will get shit on by champs such as irelia, because with how her kit works she can stun you when your passive procs, and then out sustain your weak damage afterwards (Her stun is 2 seconds, your passive at this point is 3. Big issue for your dps). He can also struggle against ranged champs, as catching them in a minion wave can be very hard.
But seriously, do not max Q. It is asking to get stomped in lane. His Q is a lategame spell right now. It does no damage early even when maxed, and is really just an awful lane spell in general.
E offers far more damage, and W offers far more utility. So, to answer your question, yes, one of the problems is you people suck shit at reworked ryze.
EDIT: I just found this forum post from a ryze main who actually repeated exactly what I just said, with some variations.
http://www.reddit.com/r/summonerschool/comments/3697c0/my_first_impressions_of_the_updated_ryze_new/
Even has a video. Educate yourself. Stop bashing new Ryze so hard, he is not the whole problem