If you were the only person left on earth of your gender and you found one disgusting smelly arrogant person to mate with to save humanity woud you?
Well, if everyone's gone then there'd be no one to deliver my baby except for smelly-arrogant-lover-boy. In the event that I had a boy, I'd likely have to mate with him (also not cool) or mate again with smelly-arrogant-lover-boy and hope for a girl so the two kids would mate. However, incest kinda messes things up genetically, so the whole process would really be quite a waste. Sorry humanity, you'd end with me.