[heRS]

How sad for the family. As a dog trainer I acknowledge all your arguments and maintain that if you start with a dog with a crappy gene pool and you know what you're doing, you'll probably end up with an okay dog. Get a dog that is an exemplary specimen of the breed your job will be that much easier. Get a dog with crappy breeding coupled with an owner with no knowledge or understanding of what they got, and there's trouble.
I'm alarmed at the number of dogs coming out of shelters that are pit mixes with no training going into the hands of people with no understanding of the dog they're inviting into their home. Recipe for disaster.
There are good breeders who know what they're doing and are breeding better dogs, better temperaments, better structure. You have to pay to get these kind of dogs though, and most people just don't want to pay that kind of money so they grab any puppy off craigslist, breed it to whatever to get their money back, and more genetically impoverished psychodogs hit the streets.