It's really rude isn't it?
I'm the first to admit that I'm pretty hopeless with remembering names the first time I meet someone. I usually don't take the name in and then struggle to remember it afterwards but if it's someone I'm going to see more than once I'll take the effort to try and make sure I know it.
Where I work there's a woman who comes in every week for an hour-long appointment with a psychologist in our department. And every week she doesn't have a clue what the name is of the person I'm supposed to be seeing. And I find it appallingly rude - this woman's given an (admittedly paid) hour of her time up every week to help you with whatever problems you have in life and you can't even be arsed to remember what she's called beyond "that woman on the third floor". It really, really annoys me.