That sounds horribly toxic and corrosive for a dinner party.

It sounds pretty useful for when you're chatting while waiting for the bus and there's someone on drugs there screaming obscenities.

Unfortunately the Internet is both.

It is the website owner's decision to allow people on drugs screaming obscenities on their platform. They are allowed to kick those people out, and you're allowed to leave if you don't like the people in that community. Good moderation is a requirement for healthy communities.