I have one, Snot, who also refuses to eat anything that isn't cat
food. She is the only cat I can have wandering past a leg of lamb of
something and know she wont touch it. Boof on the other hand likes to
eat muesli (granola?) from MY breakfast. He likes people food, and
even eats sultanas, though I tried to tell him cats don't eat them :)
The other three cats are in the middle, prefer cat food, but will eat
people food if they have to (or it smells lush).