1. Nature Vs Nurture argument
My mom runs an animal rescue and most of the dogs that she gets are dogs that breeders have abandoned. Case in point my Beagle Chihuahua that a breeder left in a rubbermaid box at a very young age because no one adopted it.
I've seen some of the most "viciously labeled dogs" go from little assholes to great loving pets just by how you treat them. Dogs aren't dumb. Treat them with respect and love and you will get the same back.
Hypoallergenic is for sure a much better reason for buying from breeders than buying some "pure bred, beautiful, loyal, whatever bullshit" they sell you on.
/rant