TLDR: Some canine behaviour is in the genes and while upbringing and training are important, they're not everything. It's not irrational to be more cautious of certain breeds than you are of others.
Longer version:
The thing is, different breeds of dog were bred for different things: herding, livestock guardians, gun dogs, whatever. While you can't say 'all terriers are yappy and likely to nip', because of the original purpose of terriers (that is, the small ones, not black russians or staffies, which are not 'true' terriers in that they are not earth dogs) was to go underground and bark like hell. The closer a terrier is to working ancestors (that is, to dogs intentionally selected to go to ground and bark, or rid a woodpile of rats), the likelier it is to be a vocal vermin-chasing machine, and the less likely it is to be happy with life as a lapdog. It might still make a very happy lapdog, but it will be a lapdog that stands in the window and barks.
Similarly, huskies were bred for their sled-pulling capacity. Provided they let people harness them up without biting off anybody's fingers, and could run for miles in the snow, they stood a chance of passing on their genes, but no one selected them for their willingness to cuddle up with the humans inside the igloo. That is not to say that cuddly or lazy huskies don't exist, but in general, a husky is likely to be high-energy, and perhaps not as tuned in to people as a dog from a long line of dogs bred for companionship.
I have a dog bred to hunt and retrieve, and the day he caught a mixy rabbit, be brought it right to my hand, never having been trained to retrieve game in his life. There is a reason that shepherds go looking for puppies with working collies as their parents, rather than (say) pet-bred Airedales, and why anyone contemplating acquiring a gun dog might consider a springer from working lines but won't be thinking about a GSD.
I didn't want a staff when my DC were small because I didn't want a dog with massively strong jaws with 'bite and hang on' probably floating around in its genetic code in the same house with children. I know that many staffs are lovely gentle dogs, but some of them are not, and the crushing power of their jaws is terrifying. When I go walking, I am cautious of staffs, and having had one take a chunk out of my dog, I don't think I'm unreasonable.