Tech companies don't have a problem with people saying "Thanos did nothing wrong." They won't even slap it with a "lacks context" tag if somebody says it. It can be said with impunity; and, as a preface, it should be an opinion that people should be able to express freely.
Just think about what that meme actually means though. Although you can't call Thanos a racist or a misogynist being that he presumably wiped out half of the creatures in the universe entirely at random (except for himself), anybody making that statement are advocating for mass murder.
Why are they advocating for mass murder? Well, it's because they believe the same Paul R. Ehrlich bullshit that a lot of people do - that there's a population bomb.
Matt Ridley pretty well put Ehrlich's thesis in it's place, as many people have. Humanity has become more prosperous as our population has grown.
So, there's no problem with social media censorship when it comes to advocacy for mass murder based on false information. So, compare that to the stuff that does get you banned. I was suspended for a joke in which I described my job as, "I shine bright lights into people's faces before I shoot them."
Does any of this make logical sense?