The difference between 10% and 20% is a few bucks. The ten percenters tell you that a few bucks here and a few bucks there, it adds up. Yes, true. But also in the other direction. A few bucks won’t matter much to me, but some server who is exempt from even a minimum wage will appreciate it. (I used to have these conversations with my father. I never won, of course, but I tried to make sure the servers didn’t lose.)