When I rode my idea of defensive riding was staying as far as possible from cars. Unfortunately the Phoenix metro are has long ago become too damn dangerous to ride. I want to get a bike, but mainly for short trips, night time, and out of town. Riding here during the day, especially during rush hour, is borderline suicidal no matter how careful you are. So Cal is even worse. I bet the lane splitters don't have a long life expectancy.
And someone else brought it up, but I have to agree: guys on cruisers generally ride more sanely. It always seems to be the young dumbass punk on a rocket who is acting like an idiot.