"These people must be thick skinned as well as tone deaf and I'm not sure how you could deal with them without being rude."

I don't think there's usually a need to be rude - some elementary communication skills may be required though, and these do seem to be in short supply. There are people out there who need things explained to them; they don't pick up on the non-verbal cues - it's not necessarily their fault; it's the way their brains are wired and perhaps the nature of the family they grew up in. People like this simply need social rules explained to them, and often appreciate that. I have seen countless instances of people being rude in sessions, but have not often seen someone turn to a neophyte and explain what's going on ...

By the way, I'm not a master of communication skills myself, but I do try to find ways around out-and-out rudeness.