Earlier quoted context omitted.
I suspect the reasons are (generously) keeping them out of the hands of people who would treat them poorly and perpetuate the stereotypes, or (less generously) ignorance and fear.
How they're raised makes a big difference, but natural instinct is natural instinct. It's just like how chihuahuas were bred to be small, but pit bulls were bred to fight other dogs.
Speak about natural instincts... I answer that some people have zero clue what to do with a dog.
I say we put down all these golden retriever too !