Not really the same thing, IMO. You're not asking someone who's bipolar not to feel emotions, but to make an effort to keep them in check so far as not treating other people like shit? That's perfectly reasonable. If a person knows that their condition makes it difficult to be around other people, then a host should be told that in advance, and every effort should be made to say, hey, I know that sometimes I come across as difficult but I really do appreciate everything you've done, etc. etc.

Also, there's no mental health issue that forces you to mooch off others when you have the money to pay your own way. Having social anxiety disorder or a mental health issue is not an excuse to behave like an asshole.