I did have a Fed Ex worker literally throw my package at the side of the house and leave one time, when no one answered the door quickly enough for his liking. (My dad had almost reached the door and through the window saw him throw it . . . I was in my room and actually heard the "thump" against the side of the house.) That only happened once, though.
I feel Fed Ex and UPS get more workers who don't give a rip compared to the USPS. The good news is that most MLPs are durable, so we don't have the worried that collectors of, for example, fine china would have. And most packages arrive safely one way or another.