I think the problem is that many of the crossbreeds dumped in the pound are from unethical breedings by people who dont understand what an ethical breeding is.
You can get breeders of registered pedigree dogs who are unethical, however sticter rules are forever reducing this, like compulsory screening for genetic diseases etc. There is no such checks on the breeding of crossbreed dogs.
Crossbred dogs are reletively common in the working world, however serious breeders of theses dogs are experienced in what they are looking for. This cant be said for the people who want to breed Fluffy because she is sooo cute, or the pet shop down the road is offering good money, or a certain cross has become fashionable.
I think it is a myth that all crossbreed dogs are healthier and random matings can be disasterous. The Pedigree world can also shoot itself in the foot by in some breeds chasing extreme characteristics in their breeds for the showring.
I cant say I have a problem with what 99bottles is proposing. However good structure, history, temperament and health testing are essential as is the welfare of the puppies produced, but that seems to have been covered.