The problem is, that the dumb rules are enforced and the good rules are routinely ignored.
Illegal turns, failure to yield the right-of-way, improper merging, passing on the right, and puttering along in the passing lane (which provokes people to pass on the right), and various other forms of careless driving are all more dangerous than speeding. Single occupancy cars in the HOV lane or cars in general in the bus/rail lanes muck up the flow of traffic a lot more than speeding does. And then there are those pricks who drive into an intersection when there isn't room for them on the other side and stop in the crosswalk, or even in a crossing traffic lane; turning a traffic slowdown into a traffic jam.
But much of the above is routinely ignored and unpunished, while the vast bulk of traffic enforcement is based on catching speeders; often on the freeways, where the potential for them to harm themselves or others or to disrupt the flow of traffic is at the minimum. It's ludicrous.