I'd never date rude or confrontational people. I'm one of those overly cheery hyper-optimists that exude positivity and I don't like to be around negative people for extended periods of time.
I don't think I'd date anyone with poor mental health. This might seem insensitive, but I've been in a relationship in the past with someone who suffered from MDD (Major Depressive Disorder), and suicidal tendencies. It was really emotionally draining, and hard for me to deal with. Over the few years I was with her I changed from a very sympathetic, emotional person to who I am now, an apathetic dude who has trouble speaking about serious issues, especially those dealing with negative emotions.
But thankfully I don't really need to worry about dating. I have Holly, and expect to for a very long time. :)