Do women expect guys to hit on them all the time?

i don't hit on women, because i have too much pride and dignity. i have no problem w/ this, but sometimes women, especially ones that i know, seem to be upset, and i think it has something to do w/ the fact that i never signal any kind of attraction. i'm just too absorbed in whatever it is i'm doing. i'm polite and cordial, so i don't see the issue. why should i feel like i'm doing anything wrong?