Some people just plain stupid.
I take my daughter to swim practice Mon & Fri's at the local county Fitness Center. Well, everytime there is a vehicle that is illegally parked in the handicapped space or spaces. So I now have the local police on my speed dial and they are usually out there within 15 minutes and issue a ticket to the violator. Well, last Friday I called on a Gold PT Cruiser, cop came and ticketed. Yesterday, the same car was there so I called again and they got another ticket! I hope and pray they are there AGAIN Friday, that will absolutely make my day! I hope the 2 tickets they've received were worth their convenience by inconveniencing someone who really needs the space.
I've called on several other cars and have never seen them 'repark' in the accessible spots, so some people learn, some don't.