You are reading into things. I never said anything about purebreeds being more worthy... I was talking about the breeders, not the dogs. There are some really nice mutts out there. I've seen a few do very well in a variety of venues. But, anyone who breeds a mutt on purpose just to make a few bucks of the cutesie designer name, is in my opinion, a fool. Again, breeding for money. You took offense because you have a designer breed. Never did I say he was worthless. Again, I'm talking about breeding. If you want to purpose breed mixes and try to establish a new breed or designer breed, great, as long as it is not just for money, and you have a plan, a goal, and have a clue how to achieve your goals, hey all the power to you. If you are breeding because you think the puppies would be cute, or so your female can experience it, or because your doggie is the bestest, you're committing an injustice. I have actually heard all those reasons...
GSD's were not intended to be 'just pets', I can't help it if breeders sell them as such. I can't stop them from breeding as such. But I can say I don't think it's right that they do it. If a GSD or Rott "pet" is from lines that haven't been bred for work in umpteen generations, but just to sell as pets, then that's the breeder's bad in my opinion. If they were bred for work, they can live as the family pet just fine, AND be trained as the family guardian. Nothing about PP training counters family pet, rather, it supports it. PP training teaches a dog confidence and lack of fear, and teaches them that biting is only OK when the command is given or in the face of overt aggression. Fear biting is the main reason dogs bite. PPD's don't fear bite. They make safe, happy, family members, who also happen to have a job. In 20 years of having PPD's in my home we've never had an accidental bite, or so much as a nip, for that matter. In order for them to be put in a fight / flight position and ALWAYS choose fight, however, requires a particular balance of drives and very stable nerves, simply not found in most breeds. Most breeds have a genetic predisposition against biting humans, and will only do so out of fear or if sick / injured. Not good in a PPD, and of course, choosing 'flight' isn't any better. Occasionally a dog not bred for it (mixed or not) pops up that can do it, but I've seen a great many more wash out on day 1 the moment the decoy yells or advances on the dog agressively. You'd have better luck w/ sport training in these cases, because sport training can be done through the lens of 'tug of war game'.