Why do some drivers think it's ok to pull all the way onto the crosswalk when a pedestrian is trying to cross the street?

The lack of common courtesy and the abundance of self-entitled, self-absorbed, SELFISH people astounds me.   I have had pissed off drivers behind me honking and raising all kinds of fuss because I will slow down and stop for pedestrians, even if they are jay-walking.    People have honked at me for slowing down and pulling over to the right to stop for emergency vehicles, lights flashing, sirens blaring...   Many people just suck.