I think it's an information asymmetry thing. I don't like it when people know more about me than the other way round, or at least don't like it when they make it obvious.
And specifically with birthdays. I'd be pretty annoyed if flight attendants started wishing me happy birthday, I hate it when people do that. I like to keep my birthday a private event. I barely tolerate work buying me a cake and singing happy birthday, and that's just because I get cake and everyone else in the office enjoys the whole thing.