You are refering to freedom of association and you are correct that platforms should be able to choose their customers if they want to. If they do that however, they will be held to account for their choices they make in contrast to platforms that allow more freedom of opinion. Makes sense, doesn't it?

Some people say allowing certain content is a statement of endorsement. "Silence is violence" and similar argumenents, but I disagree with that line of reasoning.

"Throwing shit at people and hoping it sticks" is something I do associate with accusations of racism to be honest.