FWIW I think it's a sign of intellectual dishonesty to complain vaguely about censorship of "widely held beliefs" without stating what those beliefs are. All social networks have "ground rules", they're just not always the same. For any social network that somehow can be pinned to someone's physical identity, those rules will at least include the laws of that person's jurisdiction.
"Free speech" is widely mocked as a supposed principle because it's a rallying call, not a specific thing. Even people who'll proudly tell you "I may not agree with what you say but I'll defend your right to say it" will have limits if you keep pushing them on it. "Free speech" just means "I want to be able to say things I'm not allowed to say" and the first response should always be "what and for what purpose".