Your whole second paragraph is incorrect, people posting that on Parley had their forum shut down. 99.99% of Parler is benign (often conservative) content, yet they are being shut out for having some of the wrong people around them.
That doesn't matter though in the context of what I said above though, what someone else may post on HN or their moderation policies shouldn't impact my content or my access to it.
Amazon is a private company and can do whatever it wants. It could ban apps that don’t use the oxford comma in written communication just for giggles.
Parler repeatedly refused to take down TOS violating speech. As far as 99% vs 1%, well persecuting the majority for the actions of a minority is very “patriotic” and an american tradition just ask a muslim ;)