^^^yea, that's the thing with me. If the guy is foot faulting by an inch to play a baseline point, he's actually at a small disadvantage in recovering on deep returns into his body or deep into a corner. I don't mind taking advantage of that.
But if someone is gaining a few inches on a serve and volley game, I'm inclined to mention it to them. That's just like false starting in a 100m track race.