I am lousy tipper. People make jokes about it and all I can do is laugh because it is true. I have quoted Mr. Pink many times. If you are busy I should be last to be served because I am a lousy tipper.
I see tipping as doing two things: it empowers and encourages. Giving anybody money empowers them, and they will be encouraged to repeat whatever it was they think got them the money. The thing is that the minimal relationship makes it hard to make a tip encourage anything else but there are very few people I would want to encourage to be servers. Most of them are simply bad at it or I can see them doing something better with their lives. It is rare to find somebody who is specially tailored to be a career server. But these people I tip when I find them. There have been a few.
Also I think I have something less valuable to me and more valuable to them that I can give. Mainly patience. I am rarely in a hurry so I typically don't mind being the last one served. I don't drink coffee so I don't need it filled every 5 minutes. I don't eat dessert so I don't mind you not asking. And when you do finally get around to giving me the half-assed service that I am not going to tip for I am polite and curtious. I can try to make your job, and hence your life, easier with my wallet intact. But if you would rather my money than my attention you can send someone else over. I'll wait.