Loose labs aren't making up a significant amount of dog attack fatalities.
The bad owner bit is nonsense as well. There are tons of reports from actual pit attacks how the dogs were well trained family dogs. Well trained/cared for pits can snap and when they do it is terrible. Labs have bad owners as well, why aren't they a significant part of dog attack fatalities despite their vast numbers?
Pits genetically are way more dangerous, that is a breed issue.
Pits are illegal in a lot of countries and I doubt it is just because of bad owners.