Both Fausts parents were over-the-top-DA/HA... they had to be euthanized because they simply could not be handled safely. I, personally, think that it was caused by their owners/environment... man-made.
I had some misgiving when I brought Faust home, and as a puppy he was a bossy little shyte... but he has turned into one of THE most even tempered dogs I ever had the pleasure of living with.
Nothing, and I mean NOTHING, fazes him. He is not skittish when put into new situations, he gets along w/everyone, he is extremely good natured, he is up for just about anything you ask of him - but would I want to breed him? No. He comes w/a set of health problems that would most likely affect at least half of the puppies in a litter sired by him.
I am glad I got him neutered.
Same goes for Sepp. He inherited some of his Dads healths problems, and I wouldn't wish those on any potential puppies and their owners.
Micks Mom was one of the friendliest and most even tempered dogs I have ever met... and Mick was one of THE most fear-aggressive and "dangerous" dogs I've ever been owned by. At four months old he wanted to take your face off if he didn't know you.
"Breeding for good temperament" is a crap shoot, IMO.
Dogs will never become extinct... as long as there is no shortage of irresponsible idiots, there will be no shortage of puppies.