Why the pit bull in particular, I wonder? Have pit bull dogs always had such a "bad boy" reputation?

My parents' former next door neighbors had two Rottweilers, a mother and child -- and they were always in the back yard, never got any petting, play time or special attention. They were out there on hot days, freezing cold days, rain, snow and everything in between. We used to give them a pail of water over the fence in scorching hot weather so they would have clean water to drink. I tried talking nicely to them but they would just run along the fence and bark. That family needed the same kind of screening for potential dog owners because they would (should?) have failed.