I'm sorry, I'm not getting what you're saying there.
I'm under the impression that you are attempting to argue that tipping culture is already present in the automotive repair industry. What I'm saying is that it's not. At least, not in a way that is remotely comparable to the food service industry.
If I were to walk into a mechanic's shop and say: "I need an oil change. I'll pay you for the oil and for the use of the equipment, but I'm not agreeing to pay you any labor costs until the job is done. And when it is done, I'll determine your hourly labor rate based on how happy I am with the job. And just so you know, I don't like your tattoo, so don't expect me to be generous." there is no way that mechanic would shuffle your car to the front of the line. You'd be lucky if he agreed to do the job at all.
When you (general) walk into a restaurant, you don't even need to say the above, because everyone already understands that that is the situation.
So my question is, if the above dialogue wouldn't work for getting better service out of a mechanic, why do we assume it works on servers? What is different about people in the food service industry that they tolerate that situation? I don't think those people are different. I think that society has, over the years, tolerated tipping culture to the point that we have reached this ridiculousness.
These restaurants are trying to change that. I fail to see how that's not a positive thing for everyone.