You know I am a big fan of rescuing shelter pets as well (I have 2 in my home of 20 dogs - one is deaf) BUT there is a HUGE difference between adopting a shelter animal and adopting a well bred, breeder puppy. Shelter animals usually come with some kind of temperament issues and they also come with unknown health issues (baggage). It takes a different kind of person to adopt a shelter animal - and folks that are not prepared for the difficulties associated with a shelter animal are the ones that will turn around a deposit the same dog or cat right back in the shelter not long after they take it home. It is not a crime to breed more dogs - provided you do your homework FIRST (before you ever make the decision not to alter your pet) AND you are prepared to take responsibility for the puppies you bring into this world for the rest of their lives. A reputable breeder (even if they just have one litter) makes that committment and I think has ever right to have a litter of puppies that they have thoroughly planned for, and are prepared to take back at any time in the dogs life.
My second shelter dog came to me deaf (I was aware of this when I agreed to take her). The first had MAJOR temperament issues, took over a year to housebreak because she was a submissive, fear urinator - she was afraid of everything-, and at 18 months old was diagnosed with inherited luxating patellas that required a $2000 surgery to correct or she would be crippled. I understood the complications that can arise with a shelter animal so I had the heart and patience to pay the expenses, to take the time to help them overcome their difficulties, and to commit to them for life. Not every person can do this, which is why many of these animals go in and out of shelters. It's not breeders in general that should be warned against - it's BAD breeders as the majority of pets in shelters are poorly breed, ---and pet owners that don't understand the commitment they make when they agree to adopt an animal.
So before you tell folks not to breed or buy, take that into consideration!