I'm about as far left as they come, but yeah it's definitely a fairly strong left wing echo chamber, and thay absolutely can very quickly become a problem.
I'm not even talking about "silencing the right" or whatever those chucklefucks want to complain about. We're not there yet (nor are we particularly close at the moment), but I've seen plenty of communities turn into a hivemind because they're not careful about that sort of stuff.