I've talked with people who argue that they should be allowed to have the sort of conversations that might offend people because if someone is offended, they don't have to be part of it. It's a seductive idea, but it won't
Why? Because there's a ratcheting effect. If you could measure rudeness, a chat might start at 1. People who don't care for that level will leave. So now the chat can start moving toward rudeness level 2 with fewer people to object or moderate.
Where is the limit? Well it will trend toward the comfort level of the most committed members. If part of the "value" of a chat is that it's "honest" (read "rude"), people who don't value that will leave. Problem solved? No! The next level will offend another set of people.
This is what make me so uncomfortable about the ignore feature. It gives people the idea that the way to handle rude behavior is to look away. On an individual level, that's not a bad technique. Why put yourself though frustration if you don't need
But for a group, it's a disaster. It just creates a situation where many people feel powerless, unheard and left out. At some point someone speaks up and discovers it wasn't just them. Now everyone is in for a world of hurt and misunderstanding.