I just think that some dogs have more aggression genetically programmed into them, developed over decades, centuries or in some cases millenia. I think it is safe to say that grey hounds are generally more docile and gentle than pitbulls or dobermans.
Then you've never lived with a Rottweiler
I grew up raising Labradors. At one point, we had 5 in the same house. I will say they are more naturally aggressive that a Rottweiler. You're also talking to a guy that goes & enters dog shows. Rottweilers always get the bad rap for whatever reason but it's the little 20lb dog that if you're not watching, will bite you a take a chunk out of you. Most Rottweilers act very juvenile & immature. Ever play with a puppy? Well, thats pretty much a Rottweiler.
You should really educate yourself first hand with the specific breeds before making any claims. I would also go far as saying that all pitbulls are the same way that I've experienced except for the ghetto drug dealer dogs.
Oh...greyhounds....sure they race them because they're fast...but they are also a breed with a high prey drive.
You're come across pretty dumb the more you write