A lot of reasons why people would continue to do this:
* Quick, easy money.
* Even in crowded areas people tend to walk away and not want to get involved.
* Some of the thiefs are minors which tend to not be charged with adult crimes.
* It is rare for the police to actually catch someone in the act. Easy to say you found the laptop/backpack/purse on the ground.
* The police don't want to bother because they have too many worse crimes to deal with.
* The police don't want to start a car chase where someone could end up injured or killed.
* The police don't want to start a gun fight over this type of crime.
* The DA doesn't want to prosecute these "petty" crimes because the prisons are already overflowing.
* Easy access to simple tools to shatter car windows.
* Society blames the car owner for leaving flashy objects in plain site and consider it attracting the theft. ("Victim was partly to blame.")
* Some of the thiefs are high on drugs and are acting irrationally.
* Some of the thiefs live in a gang area where getting shot is a daily risk, and being in prison could be safer.
* Some of the thiefs are pressured by local gangs to do this crime to show their loyalty to the gang (or else they get shot back home.)
* Some of the thiefs enjoy the thrill of doing something risky and getting away with it.
* Some of the thiefs are hopelessly brainwashed by a consumer marketing society that says you have to have piles of bling to be liked.
Also, in California one has to prove that the car was locked to prove that they "broke in"...
California Senate Bill Targets Loophole In Auto Burglary Law