Intersection Etiquette

Why is it that Philly/New Jersey driving have such incredibly poor etiquette at intersection and crosswalks?  It is a phenemenon that has irritated and sometimes appalled me since I moved here 8 years ago.  Does everyone think that crosswalks are just street tattoos meant to break up the monotony of the stretch of asphalt?  Do they really think that the world SO revolves around them that they are entitled to the right of way regardless of rules and common decency?  In Bryn Mawr at least 95% of cars routinely  ignore even the crosswalk that has flashing lights that light up when someone requests to cross the marked crosswalk.  How IS it possible to routinely and consistently ignore flashing lights with a person standing at the curb or even in the street itself?  I have long ago stopped complaining about the people who run the yellow/red and who jump the green when making a left turn.  But I refuse to stop finding the act of nearly running over pedestrians in crosswalk an acceptable act. None of us are that important.  Running errands, making it to the manicurist, even making it to work isn't that important that a person can't spend the 10 seconds it takes to stop for someone.  I find it sad beyound belief that when I stop at a stop sign the waiting pedestrians don't actually believe I'll stop long enough for them to cross the street.  Yesterday I practically had to wave semaphore flags to convince a group of pedestrians that I really was going to wait for them to cross the street.  So I will continue to stop even if it appears that the jerk behind me may end up in my backseat.