I tip, and I tip well. As long as service is *decent* and Im not searching for my drinks or food or whatever. And obviously as long as they are polite, they will automatically get 20-25 almost every time. On smaller bills is when i tend to tip higher.
I worked at a small italian resturaunt where i think the most expensive thing on the menu was about 8 bucks. Working lunch hours many people just came in, got a 5 dollar sandwich and water, ate and left. If they had lived by the 15 percent rule I would have made nothing. When i go to fancy resturaunts such as Mortons or something...the percentage shrinks but never below 20.
However, as the saying goes... "shit in, shit out" you give me crap service, you get crap tip. I never walk out without tipping, but if you have given me terrible service, i won't hesitate to leave you a 1 dollar tip. That way you know that I didn't "forget". Ive been known to speak to the manager on the way out as well.
I have also been seated, ordered drinks, forgotten about, and then found the manager, told them we were taking our business somewhere else, and why.
I really don't ask a whole lot from my servers, but whoever made the comment about some of them just feeling entitled to a tip no matter what was spot on. Unfortunately that seems to be my generation and their sense of entitlement.