One of the many reasons I left the USA. Too bad US-Americans are so used to tipping 20% they even do it when traveling... giving the rest of us a reputation as being suckers.
It's pretty nice to go to a cafe, pay a fair price, and not be guilted into 20% extra by a PoS machine.
Are you worried the machine will think less of you if you don't tip? Where does guilt come into it?