I'm not surprised (and empathize with) people who are reacting to the inefficiency of The System ("why don't restaurants just charge more and pay their employees reasonable wages?"). This is correct, but as others have pointed out, in the US at least we seem to be stuck at a suboptimal local maximum in this area. It would be impractical (and maybe catastrophic) for any one restaurant to suddenly adopt this policy, so that's not going to happen anytime soon.
Rather, I'm always amazed at the portion of people who have a visceral reaction to tipping due to what appears to be just plain lack of empathy. These aren't the people who are saying, "why doesn't the restaurant just pay better?". That totally makes sense. These aren't the people who tip less (or not at all) when they've had a really bad experience with the server. That makes sense too.
Specifically, I'm talking about the people who deep down inside just always have a reflexively negative reaction to directly giving their money to the person who just served them. These are the people who feel happy about themselves when they say things like, "my tips start at 0% and go up from there", or who seem to put way, way, way too much mental energy into grading the level of service that they've received and coming up with a number that reflects that level of service each and every time they go to a restaurant. If anyone posting is that kind of person, please just shut up and start being a better person already. I encounter these people all the time in SV. These aren't poor people for whom the tip is ever a meaningful amount of cash. These are people making many times the annual income of their servers, getting continually worked up over a few dollars, supposedly because of "the principle of the thing". These are always people who have never worked in a restaurant, and are almost always people who never even had a job until after they got out of college. If anyone posting here is posting for this reason, please just get over it and find more constructive things to get worked up over. Ideally something that doesn't directly impact the income of people making way the hell less money than they do.