Hmm.
I've had many situations/social-groups in my life where I was kind of the only guy speaking. Not because I was being an asshole (although maybe I was,) but primarily because I felt that other people were uncomfortable. Nobody likes awkward silences.
It works. You can start some conversation. People do appreciate some guidance.
But. Never, ever, did this tactic produce an environment where people are truly being themselves. Free, secure, enthusiastic- everything you want on a platform. Agreements, disagreements- everything.
Then it dawned on me. Shut the fuck up. Let the people decide for themselves what they want this to be like.
And it worked. Someone always says something. Someone else responds to that something. The quiet guy suddenly jumps up because you touched a sensitive topic. Someone else calms him down. Everybody leaves with a story to tell.
Don't really know much about other alt-Twitters or why they failed, but general logic says you should always leave as much room for culture to develop organically, on its own, as possible. Some lines shouldn't be crossed, but other than that, just let people do their thing.
I've also been to many places where someone always tries to hard-control the whole social thing. It. Never. Works. Not with your barbeque Sunday, not with Twitter.
Or, again- it works. But only to an extent.