Conservatism has a place in society. Racism, bigotry, hate, and white supremacy do not.
The fact is that American "conservatism" now is so run through with hate and vitriol and othering that no one can tell where one starts and the other begins.
The logical fallacy that this is a "slippery slope" is ridiculous, and the number of people who are crying about losing the "freedom" to attack, incite, and threaten others is astonishing. The number one terrorist threat in the US right now is right-wing militant groups, condoning threats and violence towards anyone who thinks different than them.
It's pretty clear to most that deplatforming people with hateful, violent, and dangerous messages is less of a threat to society than allowing them to keep spreading their vile hate. This isn't some arbitrary thought experiment or a white-room theorycrafting; people are dying because of this kind of hate.
Conservatives who distance themselves from hate and bigotry and violence are fine, and I can live with those people, but the American far-right are a blight on society and private corporations are within their rights (and, I would say, responsibilities) to actually enforce their own policies against these people.