Because:

1) Judiciary positions are political appointees. They've become political animals instead of the objective thoughtful judges we need, and the more we have who use the judiciary as a pulpit to perpetuate their personal political opinion in order to advance their career.

2) The Supreme Court, being a lifetime appointment, is supposed to free judges from political pressure -- but in order to get there, they are already affected by point #1. In addition, the S.C. does not make all judgements of Constitutional law, it is merely the court with the most authority, and as such only reviews Constitutional questions.

3) The courts don't get to review every law -- only those which go through the judiciary process.

4) Because the US is under common law, the precedent of those opinions is as important as the law itself. So if an unconstitutional law gets upheld by a court for political reasons, it will be perpetuated. Under common law, the law is a living entity that can slowly evolve with the times and public opinion -- for better or worse.

In theory, yes, the courts will strike down an unconstitutional law. And frequently, they do. But often these political hot potatoes are upheld until long after the damage is done -- like the internship of Japanese-Americans during WWII and Lincoln's military courts.

On the car/gun thing, I agree. We license cars for safety because they are deadly items. Unlike guns, however, another car driver on the road at least has safety devices to protect him from poorly-driven cars or accidents.

It's true that people use guns to commit crimes, but more people die of accidental gun deaths than criminal activity. Why do we give carte blanche to anyone to own a gun without taking reasonable precautions that they know how to treat it in a responsible manner? It's a positive action we can take that won't infringe on the rights of those who DO use guns in a thoughtful manner for recreation or self-defense.