[Nirvana]

I am not sure what you mean.Too many purebred dogs? Too many back yard bred dogs? Too many mutts? If there are too many how can commercial pet mills operate at a profit? Supply and demand works in that industry as well. Did you know it is illegal in MO. to photograph a dog auction? The laws in that state protect that industry. They have unions.
Most of the dogs one will see in a kill or regular shelter are mutts or dogs bred by un-knowledgeable back yard breeders that failed to neuter their family pet. Its very rare that you will see any purebred registered dogs bred by professionals in any shelters.
Animal rights activists want to control every aspect of animal ownership whether you just want a family pet or you want to breed birds.
Its is now illegal in California for chickens to be kept in confinement when they lay eggs. Next they will tell livestock producers how many animals they can have, what to feed them and then charge them $100 per animal just to have them. Say hello to $100 T-bones if you like to eat meat! $40 eggs, $200 hams etc.