It is indeed convenient, not just for individuals, but for society at large. People keep their most "controversial, rude, offensive, or downright dodgy" only to

It is indeed convenient, not just for individuals, but for society at large. People keep their most "controversial, rude, offensive, or downright dodgy" only to be said amongst friends whom they trust to not "out" them, while keeping their utterances in the public sphere more self-censored, in order to avoid offending people and being rebuked. I'm pretty sure that this is how it's always been, and I'm quite happy with it.