If someone is running a free speech platform, people should be able to advocate for all those things. Don't mistake me for a hypocrite who decrys censorship only of things I don't want censored. I'm not. People should actively discuss and advocate for positions they hold no matter the position. That's free speech. There are few limits (openly inciting violence, plotting crimes1, copyright etc)
If a platform or audience doesn't like that, they can drop free speech and become a safe space. That's their business. But they shouldn't censor speech and claim they are for free speech. That seems to be what is happening here.
Fyi, I haven't kept up on antifa or the events around them. But my position is that looting is wrong. At the same time, I'm sure they are right about at least something. That's a pretty safe, reasonable position right? Not on Parler. On Parlar that position is banned. And by banning my comment, you are banned from correcting me. How is that a positive for you or me or any other reasonable person? It only seems a positive for those who are too weak to bear hearing such simple positions. And even they are trading wisdom in the long term for comfort in the short...
Sorry. I feel quite strongly about censorship. It's a foolish idea we should have dropped back when we still had Kings and lived in mud huts.
Would you be in favour of banning people supporting ISIS, child molestors or the Nazis? Because from a conservative perspective, the rationales of one might apply to the other and so many nominally free speech environments ban support for those groups.