This is very much the case.
I made a few posts, around when the Sietch started. I later chose to not post here - not because I was afraid of peer pressure, or being criticised by people on SB, but because I felt community norms and expectations here were radicalising in a way that made the site actively unpleasant to be on.
That's not about any other site. I post and have discussions on a number of other sites, not just the ones you're probably familiar with. It is to do with the Sietch itself not being a pleasant place for me to engage. I think courtesy and civility are important, and while in my opinion Zoe takes it too far, there is a minimum necessary standard of politeness for intellectual engagement. That minimum standard is, I would argue, well above the level where you call people 'f----t' or 'c--k'. I am for civility not as just superficial politeness, but civility
as a democratic virtue.
I like engaging with diverse and controversial perspectives. I enjoy it and seek it out. But I am not willing to wade through garbage in the hopes of picking out a few gems.
I am encouraged that some staff here realise there was a problem, and that people like me chose to avoid engaging on the Sietch because of it. I hope that things improve.
There are some posters in the thread arguing that this is the thin end of the wedge. I would like to suggest to them that there is in fact room in between /pol/ or /b/, on the one hand, and a highly restrictive left-wing forum that bans any right-of-centre opinions. Conservatism or rightism do not require that you be the lowest common denominator, or that you hurl obscenities at each other. Would, say, Roger Scruton have put up with that sort of behaviour in his presence? No? Then it is clearly possible to be conservative and also well-mannered.
Just in case, a disclaimer: yes, I know I'm one of the dreaded SB staff, and thus officially one of the Bad Guys (tm). If anyone is entertaining any conspiracy theories, don't. I am friends with some of the Sietch staff, but we never discuss Sietch policy and I don't encourage anything behind-the-scenes. What I've said in this post is my personal opinion only.