People seem to hate "no problem" too. People get really touchy about the smallest things... did you know that some people take it as a deadly insult if you place their change on the counter instead of placing it carefully in their hand?
The first is an issue of formality, but outside of genuinely formal situations, balking at "no problem" is ungracious, even dickish. (In some cases, it'd be the same even in a terribly formal situation.)
The change-in-the-hands thing is a little more defensible - in some cultures, putting the change on the counter (especially when someone holds out a hand) is considered to convey that you think your customer is too beneath you to touch. It's been known to come up now and again in the US, especially between people of different races/ethnicities.
