I don't know if you realize you shifted it from you feeling you were cheating yourself and others out of something. To you "can't think of any reason anyone would feel cheated" Those seem to be very different things ....but closely related.
At least you have a good idea of what rubs you the wrong way. Maybe it's as simple as you wasting your time with someone you feel is severely flawed. And the the time and energy could be invested in your family instead.