I don't see any sea change in tipping practice without a concerted media effort (which will surely annoy me into doubling my gratuities) or government intervention. But there are good reasons to tip well, and specious ones...
The basic problem is twofold. Restaurants attract customers largely based on their menus, and there is an incentive to discount service from teh cost of the food. If Bob's Bistro is able to list $18 filets on the menu while discounting the waiter's pay, then Steve's Slop-shoot can't afford to include that cost in the advertisement. No one will come, even if Steve double-deep-fries his steaks to colon-clogging perfection. Just costs too damn much.
[This is kind of funny, actually, because most restaurants don't make their off of food, but rather booze, which is also not included in the menu price.]
The other things that keep tipping alive is the (fucking) IRS. Restaurant employers can legally underpay wait staff at something like a quarter minimum wage. (In MA, the base waiter pay is two-something an hour.) Employees need the tips to get paid anything approaching working wages. Depends on where you work, but a fraction of the tips usually go to the other underpaid restaurant schlubs: the busboys and dishwashers, and the person who cooks your food. Waiters also get screwed at tax time, as the two dollars and change is often insufficient to get properly FICAed. It's always fun to come up with a couple grand lump sum in April.
Now, the justice of tipping depends on where you work. There are advanced skills working at a quality restaurant (you need to know about the food, and how to satisfy the expectations of moneyed assholes), but as John notes, the skill level doesn't exactly rise as fast as teh food costs do. If you're in fine dining, waiting tables is surprisingly lucrative. If my wife did it full-time, she'd be coming close to her old engineer's salary. (See kids, college is for suckers.) The pay scales in fine restaurants seem a little absurd when you start comparing waiter take home pay to that of the skill players (the chefs).
On the other hand, old Mabel slinging breakfast hash is on her feet just as long (dealing with teh expectations of unmonied assholes), and earning a quarter for every plate to supplement her salary. You'd be nuts to serve breakfast, and I try to give these people a break. I think the pizza deliverer has the worst lot of the bunch, and not just for the humiliating uniform and drunk customers. Do you think Papa John's is paying his car insurance? I tip the pizza guy best of all.
I try to tip well for the first reasons. I don't tip people in fast food: these poor sots earn a normal wage, expect me to bus my own table, and don't bring my sack o' crap past teh counter. I tip bartenders less because I think they deserve it, and more because I want the drinks to keep coming when it gets crowded.
Keifus (good tipper)