I'm going to attempt to rationalize why cyclists don't obey traffic laws in cities.
The short answer is that bicycle riding in cities sucks.
It's loud, slippery, uneven, blocked, takes a lot of physical effort, is full of unpredictable giant metal things that can kill you, teeming with large moving meat pillars that will jump in front of you at any moment, you're completely exposed to the weather and can't safely look at a map while you navigate. They've created a few strips of pot-hole ridden, double parked green pavement that they say is just for you but it's not safe even if you're being safe and extremely uncomfortable. Bicycle riding also happens though to be the fastest, most liberating way to get around and is good exercise so you put up with it, but you put up with it while annoying a few people yourself. You block lanes when you feel like it's safer to do so, cross red lights when you think it's safe so you save some time and so you can stay in front of the same wave of traffic as they already know you're there. Some times you make a bad decision that results in a honk but you've also been splashed, cut-off, bumped, blocked and almost doored and you don't have a horn of your own for when that happens. You're up against a torment of danger and uncomfortable that can kill you and the most you can ever do is make someone annoyed or maybe flip a mirror back. You start to realize that the cards aren't in your favor and that annoying drivers in their crash cages, with AC, maps, surround sound, horns, gas pedals and bucket seats really isn't that big of a deal. You just don't equate your presence on the road with theirs and don't think the same laws should apply. Not because you're magically above the law but because through years of experience you can see that the situations are completely different and require completely different attention. You think to yourself, the day cars weight 40lbs and go 15mph is the day you obey all the same laws as them.