Why are pit bulls a "controversial" breed?

I saw a facebook post that linked an article, talking about a man who was mauled by two pit bulls. Police officers shot the pit bulls dead. Scary as heck, but he was walking past a neighbor’s house who had gone on vacation, saw the pit bulls in the yard, and took them in. I don’t want to be blaming the victim here, but he really shouldn’t have just taken the dog in. He assumed the owner was bad and abandoning the dog (the owner was in Pennsylvania), and maybe he had real reasons, but I still think taking in a random dog that isn’t yours without permission is a bad idea, and now that owner gets to come home to hearing his two dogs are dead.

I saw a comment on the Facebook post that said that pit bulls are a very dangerous dog breed, and they attack children, etc. I personally own a pit bull, and I have only been bitten minorly. Never just attacked without reason. I could be biased because I’ve never had a mean pit bull, but stats that I’ve seen say that only 3% are used for fighting/ violent reasons and that they score above average on temperament tests. Along with the fact that they are not bred to be mean, it isn’t hereditary.
I think the assumption that all pit bulls are bad is stupid. We think it’s wrong if we assume an entire race or religion is bad because of a few people, so why is it okay to do that to dogs?
I said that they are a controversial breed because of the views people have on them, and because of the BSLs that have been passed against them.
I get the obvious answer to this question, that they are controversial because of attacks and things, but if there are stats that prove they aren’t terrible and have better temperaments than most dogs, why do people still dislike them?

(A BSL is a breed-specific legislation that bans certain kinds of dogs based on behaviour commonly associated with that breed.)