The private/secret repos I'm talking about? They're probably operating under Fight Club rules. If you aren't plugged in, they don't even exist as far as you are concerned. You don't even know you're missing out.
I don't think this is staying out of the community. It's staying out of a community by forming another community, complete with its own set of good/bad people, rules, and expectations. Indeed, this is how many popular communities began - small, insular, quiet, before growing larger as human constructions frequently do.