Maha, openness raises serious issues, and I thank you for confronting them. I agree with you that no group should force anyone to be open, especially since many have genuine risks involved with public discourse, and I recognize that a public, open forum can exclude many from the conversation. While boundaries around any conversation are porous (there are preciously few inviolable boundaries in nature: not black holes and perhaps not even death), most boundaries manage the flows of information, energy, matter, and organization through the boundary, and they try to exclude those elements which may damage the entity. Of course, defining and limiting damage are problematic issues themselves, and I do not know how to avoid them. One tries for kindness and understanding, but it seems to be a constant struggle.
Still, if a group of my buddies were playing a game of soccer, and I showed up with a baseball or cricket bat and started playing the ball with the bat instead of my feet, then they would be right in explaining proper behavior within the game and excluding me if I didn’t play correctly. They should not be able to force me to play with my feet, but they should be able to exclude me if I don’t or can’t play with my feet. To let me continue playing the soccer ball with a baseball bat would destroy the game for all. Of course, if they love my company enough, then they could also change/enlarge the rules of the game enough to allow me to use a bat, but it would be an exception, probably a one time exception, and it really wouldn’t be soccer.