I think people hate Morgana because she's good at punishing bad positioning / lack of knowledge

Something I've noticed over the years is any time Morgana becomes a common pick people start saying she's broken or OP. Even if she gets nerfed and then comes back into the meta later without buffs, same thing.

Well here's the thing you gotta understand. Morgana is just really good at punishing you if you position poorly. In bot lane after your minion wave dies first, you have to back off. You actually have to think ahead and start backing off before your wave is gone. If you don't, Morgana will most likely hit you with a Q unless you flash. So by positioning badly against her you've put yourself in a position where you will be forced to flash or die. Her Q hitbox is pretty fat, giving her a huge advantage when you have no minions to stand behind.

Honestly I think that's fine because it gives her clear windows of strength and weakness. You should not be able to simply outplay a champion in all situations. There should be situations where you have to respect them and other situations where you can be aggressive against them. With Morgana it's very clear cut. She needs a minion advantage. That is healthy because it's a very fundamental thing about laning. People like to complain rather than learn but consider this. If you get good at playing around the minion waves, it won't merely help you against Morgana. It will help you in the majority of lane matchups.

Another thing to consider. Cait is really the problem. She synergizes with Morgana because her waveclear and early pressure give Morgana more windows of strength to work with. I think honestly Cait is what Riot needs to look at because the problem with her isn't just laning but also how she does the "get bot turret -> rotate and get the other turrets" thing way too well. This game is so boring and rote when that's a strong strategy. While it's also strong with other ADCs nobody abuses it like Cait. Morg happens to be really good with her so you see more Morg when Cait is good. And the game overall sucks ass when Cait is good.