Just out of curiosity, where do you live? I've worked front of house at many different restaurants in an expensive city on the west coast, though this was 6 or 7 years ago. I was under the impression 10% was bare minimum, 15% was the next step up, and 20% was generous.
Wow, that's a bit sensational. Using LA/NYC as a point of reference, tipping is basically a spectrum. For drinks in a bar the minimum tip is a dollar and two is a good tip. For a taxi driver 15% is acceptable for average service and 20% would be for good service. For dining out 15% is perfectly adequate for just average service and 20% and above for good service. Counter tipping is it's own special thing but generally stuffing a dollar in the tip is jar is acceptable.