I've stayed in relationships with girls before for probably too long when I knew I wasn't feeling it. I gave all of them the courtesy of a reasonable break up conversation though. It's just a matter of respect.
Even though it was destined to not work, I just can't understand how someone can completely dismiss someone they've had a good relationship with. How can someone just completely disregard someone else's feeling like that? All it would have taken was a five minute, face to face conversation and I could have been moving past all of this a long time ago.