I feel that most of the time candidates just want to hear something that puts the situation out of their control, and therefore wasn't merit based.
It's always easier to hear "I'm breaking up with you because I'm moving for a new job and want to concentrate on my career" than "I'm breaking up with you because you're awkward around my friends and aren't interesting".
It's always easier to hear "I'm breaking up with you because I'm moving for a new job and want to concentrate on my career" than "I'm breaking up with you because you're awkward around my friends and aren't interesting".