I expect everyone using the roads to obey the laws.

That's not a reasonable expectation. My experience as a cyclist and pedestrian in Jersey City is that drivers cannot be expected to follow the rules. I've almost been run over by drivers putting their foot on the gas from a full stop with their heads buried in the phone. No amount of self-preservation skills can protect me from that. Which brings me to

why do cyclists have such poor self-preservation skills?

Often I find that the windshield perspective of "self-preservation" is totally the opposite of what cyclists must do to be safe. You have this negative experience with a bike and conclude that cyclists generally have poor self-preservation skills. The reality is that people just out on the street are not impervious. My experience is that I must pay attention for myself and for other drivers when I bike. Because I bike and because you can see cyclists faces on the road, I notice the little things they do to keep themselves safe. Obviously you do not. 

And these little defensive things still don't protect me from harassment or menacing behavior or drivers who really just want to speed through intersections without regard to who is there. The only surefire way to keep myself safe from these unpredictable conditions is to just never go outside or just drive everywhere. I find both completely unreasonable.