I don't owe my servers a god damn thing. Period. I am obligated to pay what is on the bill. That is all.
Now, that being said, I tip, and try to tip well when it is deserved. If you keep my glass filled, get my food out to me quickly, and give me generally good service, you're getting a decent tip. If you neglect me, if I sit with an empty glass for a very long time, if you act rude or indifferent, then you are getting very little or jack squat. That's the way it works. Tips are a reward for good service. They are not an obligation.

This. ^
At a bare
minimum, you owe the waitstaff sufficient compensation for their time and labor. "Sufficient" meaning paying a price for the food and service that allows them to be paid a living wage. Either that amount comes from the current price (which includes a SUB-living wage) plus "tip" or an up front price to pay the living wage.
The following actually happened: I know because I was there when it did:
During a
very busy lunch rush (which we were running short-handed to begin with), a large party came in (7-10 people IIRC). They proceeded to order a proverbial ton of food. Each and every last order was a "special order" (required non-standard preparation). We were already backed up, and they were told up front it would be a few minutes.
They proceeded to make the servers' life a living nightmare. Every minute or two they wanted something else (refills, more condiments, etc). And all they did was complain complain complain. It was taking too long. They were "being ignored". Where was the food? They kept at it even when it put the servers behind on other tables' requests (which in turn set
them off). Somehow, we managed to get it out to them.
They kept this up for the better part of an hour (and several additional orders). One of the servers told me later that by the end even some of the other patrons were getting pissed at this bunch.
When they finally paid and left, can you guess how much they left as a tip for making our lives H*ll?
Not. A. Single. Penny.
So don't talk to me about how tips are an "incentive for good work". Don't talk to
anyone who has worked a tipped job.