I believe dogs take on behavior of their owners whether good or bad. Once a vicious dog is encouraged by their owner it should be put down easy. The owner? Put them down hard.
Pit Bulls have a bad reputation because of their owners. My son and his ex had a pitbull, who was the most gentle dog you could imagine. Jersey, or Cow as they called her because she had the markings of a Jersey cow wouldn’t hurt a flea so to speak.