You have a good claim, but bad evidence.
After playing a bunch of DotA-likes (or MOBAs as they're called these days), it really feels like league is an imbalanced game.
Your point that I thought was most legitimate was about counterplay. That's the biggest problem with league at the moment. Too many ways to deal damage, but hardly none to avoid it. I know that all mobas are based on player skill, but to a point, league seems to be based more on numbers than plays. Your plan can be as thought out as you want, but 3 yasuo crits at 11 minutes in will stop it either way. From what I see, the characters considered best are the ones that can put out damage and CC most efficiently. Armor and Magic resist help until they get penetration, making what you spent gold on useless. Why would a game allow 100% crit chance, but have no dodge chance? You can't avoid autoattacks after the animation, and if those attacks can do upwards of 300 damage, 750 with crit, that's bad. AP scaling is also pretty ridiculous. After a few items, Katarina can shred through champs. It used to be fine when she could be silenced, but unless you're Fiddle or Malzahar, that's not going to happen. Even if you do have a silence, what will that stop?
I have never played a MOBA where I fear the very CONCEPT of going against a specific character, like a Riven or a Wukong in lane, regardless of their player's actual skill. I'm not one to care about specific characters and their balance, but the balance of the game overall, yet many characters very clearly stand out from the rest. All of this leads to meta, which isn't a bad thing on it's own, but makes league worse with it's presence.
"Adhere to the meta"
Out of any moba I've ever played, I haven't seen so many tier lists. If characters are that easily put in order of usefulness, that's a bad thing. I always hear that it's about how you play the champ, and that's very true. However, if I'm running my top lane Galio vs. my opponent's Fiora, he will have an advantage. I'd have to put in alot of effort just to keep up, while if Fiora puts in the same effort, I'm done for.
I put up many arguments about league's balance, damage, meta, and all that. But it doesn't truly matter at this point. I'm not going to say that it is, but league may be imbalanced for a reason. LoL is Riot's only game. For riot to continue making money, they need players to invest in the game, to get attached, to feel like a part of the system. So, by setting new trends in champions, players will always be buying new champs. When they start winning as these champs, they'll feel good enough to buy a Skin. This process of an ever-changing game creates very dedicated players, who always wish to be "in the know" or "the very best". It also gives them a great sense of community. All of these factors combined really do equal profit.
Meta, Imbalance, and Winning keep players happy, entertained, and dedicated. And for what it really matters, that's fair.
& 
. Forgot what patch was that.
