Yeah, like I’ve always tipped the “standard” (15% here) as the minimum in the worst cases, my standard is 20-25% or more depending on the bill and time of service, et cetera; and they still had their panties in a wad over the idea that their brilliant shortcuts weren’t that brilliant and that someone might still see through them or at least appropriately judge their service over them, intentional or not.
edit: at the time it was 25% or more; I’ve only adjusted it slightly because I don’t make as much anymore, and even then it’s mainly when it’s a large bill, and I’m by myself, and either the service was just sub-par, or it was a very fast but expensive meal. Good eating is my vice.