I agree with you about the perfume, but it's harder to enact - I like perfule, especially of the BPAL variety, and the only person who has ever asked me not to wear it when I come over is my dad, who is growing very sensitive to scent these days. If someone else asked me not to then I wouldn't wear it if I was going to their function, however it's less likely to have a broad proximity effect than smoking (I think, do correct me if I'm wrong) and unless people have actually had this conversation they are probably not selfish, just ignorant of the consequences.