Earlier quoted context omitted.
I really dislike the perfunctory "slippery slope" type argument. It's never an argument not to do something; it's merely a warning to make sure that you don't use an action as a stepping stone to taking more extreme actions. Saying that banning certain things is a slippery slope, and using that excuse to never ban things, means that it's ok to allow truly horrendous things to happen, just because of fear of overreach…
Yelling "fire!" in a crowded theater is not generally recognized as political speech. At what point is it acceptable to ban unpopular political speech, provided that speech is not a direct incitement to riot/violence?
I'm not saying it _is_ acceptable to do that. But we are actually talking about political speech that incites people to violence, and I'm ok with banning that.
But -- we're not even talking about _that_ here. We're not talking about a government restricting speech, and we're not even talking about an essential, monopolistic company removing a party's only avenue to speech[1]. We're talking about a non-essential internet corporation (for which there are many alternatives!) deciding they don't want to help a hate group spread their message.
[1] If their single-option ISP cut them off, we'd probably be having a very different discussion.