The correlation, unfortunately, is that those dog breeds are popular with assholes who treat their dogs like crap or encourage territorial and aggressive behaviour.
I’ve met a LOT of bully breed dogs, and when they’re in the hands of good owners they’re kind, loving, friendly, and incredibly loyal. I’ve known pitbulls who would let toddlers treat their faces like silly putty. The biggest danger they pose is a total lack of regard for personal space; pitbulls basically want cuddles 24/7.
Inherent aggression and nervousness is much more of a issue with herding dogs like corgis and collies, because they want to always be in control of what’s happening around them. But those dogs aren’t popular with dickwads so you rarely see the same kinds of issues with them.