Only my Opinion
Most dogs are a reflection of their owners
Bad Dog
Bad Owner

Their are exceptions some times
But most of the time this is the way it is.

I had a boss years back that had a Pit Bull
I went to his house to pick up some tools for a job.

He warned me about his Pit

And told me that when he rolled over on his back be prepared to get peed on if I rubbed his belly

I told hm that he did not have a Pot Bull he had a Stafford-er Terrier (or how ever you spell it).

Stafford-er Terriers are good well behaved dogs

Pit Bulls are nasty pieces of crap dogs Raised by nasty pieces of crap owners.

2 different breads.

Again this is just my opinion.