i knew some people would take exception. yes, i'm sorry, stereotypes are unfair to those who don't fit. but the fact is -- and servers will agree with me across the board -- that you are much, much likelier to get stiffed by one of those groups, no matter how good your service is for them. it's a numbers game, and the odds are against you in those cases.
But people like him are the reason I generally don't tip. They see it as an entitlement and expect it for any piss poor lack of service.
and people like you need to stick to eating at fast food drive-throughs and all-you-can-eat buffets.
if i gave shitty service i expected a shitty (or no) tip. that's why i always gave the best service i could give. like keeping drinks filled, making sure the food was delivered correctly and on time, being aware of when customer needed something... maintaining attentiveness without being fawning or obsequious. all the while helping other servers, and doing behind-the-scenes duties that all servers have to do to keep the front of the house working smoothly.
sometimes, no matter how hard you try, you just completely blow the service for a table. sometimes its not even your fault, the kitchen screws stuff up. in any case i'd apologize and own the problem, and try to remedy it as best i could, and accept the fact that i probably wouldnt get a very good tip.
now, i have a professional job, but i remember the days of restaurant work. so i give 20% for decent service. 25% for exceptional service, and 15% for mediocre or indifferent (but not bad) service. If the service was truly BAD ( and i cant recall the last time that happened ) i will write a scathing comment on the credit card slip.
writing comments on the bottom of the credit card slip is very effective. the manager must review each CC slip at the end of the shift to make sure they were entered properly. anything you write WILL get read. I write good comments for really good service (in addition to the tip). it really can make a difference for a server, to have their manager read a compliment about them on the CC slip.
i eat out a lot, and its probably been at least a year since i gave no tip and wrote a highly critical remark on the CC slip. i reserve that for truly bad service. Restaurants here in Seattle just don't have bad service. there's too many good restaurants here for shitty ones to survive long.