Magneto has repeatedly had turns of being extermonationist against regular humans, and even when he isn't he's still often portrayed as mutant nationalist, modelling his vision for Genosha off of Israel, which he has repeatedly stated his support of in a very "You lived through the logical conclusion of that shit personally, how are you THIS determined to still get it wrong‽"
Poison Ivy has turns of being an eco-fascist, and her more just being an anti-social eco-anti-hero now is often billed as being a direct result of her treatment at Arkham when before she wanted to actually kill everything but plants. Not even all humans, all everything that isn't either a plant or a plant symbiote, and while that would be am incredible spec-evo project, it would also make her the single most genocidal psychopath in earth's history assuming lichens don't achieve sapience to start making a contest of it.
For just wanting to save his wife, Mr. Freeze sure has a lot of arrests on his record involving trying to plunge gotham into a new ice age, which, just look at Extra History's series on the little ice age to get an idea of just how horrible doing that on purpose to a society is.
Stop whitewashing terrible people who just happen to even tangentially look like a cause you agree with.
That's how we get Joker being seen as justified because one too many people feel personally attacked for cat calling women to smile more and ....motherfucker I think I just figured out why the incels latched onto him so hard.