Personally, I would consider making a public post about something on social media as an open invitation to talk about it in comments. It doesn't excuse being rude or anything, but if it was about an issue in my life that I was comfortable sharing, I would expect others to appreciate giving and receiving perspective if they didn't specify otherwise.
Not sure who would be demanding anything in this scenario. People choose to comment or not, including the OP. Everyone is communicating only as much as they feel comfortable doing, unless there's context I'm missing.
Perhaps the Marxist and the anarchist should have voted when the liberal was asking who should be given the gun.