IMHO, the hassle of working out a tip is relatively minor in the scheme of things. Instead I resent that I am forced by this custom to explicitly render a judgment on the quality of service I received (expressed through the size of the tip), and I resent that I in turn will be judged by the server as being generous or a cheapskate (as interpreted through the size of the tip).
I also resent the uncertainty of what’s considered an appropriate amount. Is it 15%? Is it 20%? 25%?
Will I be perceived as a cheapskate if I tip at 15%? Am I wasting my money if I tip at 25%? Depends who you talk to.
You say that, and yes, there are a few assertive people who are willing to leave penny tips when they feel they’ve been wronged. But most people arent’ that confrontational. Frankly, I can’t recall ever leaving a tip less than 15%, even when I’ve felt the service was sub-par. And on top of that, there’s all the other stuff you said:
Putting it all together, it comes to this: tipping is poorly correlated with quality of service.
Here’s an article from the owner of a tipless restaurant, which contains the following:
Studies have shown that tipping is not an effective incentive for performance in servers. It also creates an environment in which people of color, young people, old people, women, and foreigners tend to get worse service than white males. In a tip-based system, nonwhite servers make less than their white peers for equal work. Consider also the power imbalance between tippers, who are typically male, and servers, 70 percent of whom are female, and consider that the restaurant industry generates five times the average number of sexual harassment claims per worker. And that in many instances employers have allegedly misused tip credits, which let owners pay servers less than minimum wage if tipping makes up the difference.
You’ve really never heard of servers confronting diners over shitty tips? I once had a server follow me out to my car to confront me over a shitty tip (it took a second before he realized I wasn’t the stingy bastard he was looking for).
I feel like this sort of math is no big deal, but that’s because I work with numbers all the time. But some people really struggle to do math in their heads. 10% isn’t hard, but now you want me to add two four-digit numbers in my head (to come up with 20%)? And how much do I add/subtract to get it to 18% or 22%? Some of us I can do this with little difficulty, but I suspect there are plenty of folks whose first thought when the bill arrives is “goddamit, where’d I put my calculator?”.