I am pretty sure not every breed is a subspecies. “Canine” is a family-level classification including foxes, wolves, etc, and dogs are a subspecies of gray wolf, as are dingoes. Most breeds are only a hundred or two hundred years old at most. It’s possible Darwin would have called them races but we don’t still use the word that way.
And actually you’ll find plenty of people denying that some breeds are inherently dangerous; it’s all the fault of people raising them wrong because they want the ‘reputation’.
Basically, it’s way easier for temperament to be transmitted by culture than by population genetics.