Pretty much the same as what Dakota has said. I don't believe in all puppymills being this mess of destruction. However, I still don't think highly of them myself. Puppymills treat it as a business, they usually have several dogs, purebred or not and they churn out litters at almost every available opportunity. They usually don't take the time to get all the necessary testing done, the background lines and checks, mainly because they're in it for business and profit so as long as puppies are being produced, being sold and being bred, they don't worry about the finer details. Puppymills usually don't have show quality, they don't take the time to even show their dogs, and if they do it's probably not via conformation or any AKC registered events, or luckily if they do choose one or two for that, it's only for the title so they can raise prices. I would be surprised even, if there was a puppymill who have all their dogs and breeding dogs CERF, OFA, etc approved. I somehow doubt it.
Reputable breeders don't breed all the time, they also usually don't have more than one litter on the ground, and they usually only do it once a year. At least from what I know around here, reputables don't even plan a litter before there's a long waiting list. I also find that they are extremely selective where their puppies go, and quite a few breeders that I know will strongly state that they couldn't give two hoots about what the purchaser wants, they look out for the best of the best interests for the puppy and the puppies only. Which personally, I find highly respectable. And then some.
In what you stated in the other thread, BW. I do agree that the shelter and rescue need all the help they can get. But I can understand being someone who was diligent in searching for my two, and others opting for reputable breeder pups. I like knowing where my puppies came from and knowing that they cared enough to find the right homes for Jasmine and Ori, I like knowing their background histories, the fact that everything was done in order to make sure they were healthy, even though it was unfortunate that Ori still developed HD. Ori is also one of the last pups from his mother's last litters, as she was killed by a neighbor before she had one more before retirement. Which I guess is a complete blessing that she didn't, however Ori is the only known HD case in their entire experience.
But I know that if it ever came down to it, I would have nothing against adopting or rescuing. I just opted to choose where my pups came from, or at least choosing to know where they came from and knowing that I had lower risk in raising a pup that I knew was bred respectively. I just don't find puppy mills OR BYBs respectful at all. I respect those who do it for the love and care of the breed, and who do everything in their power to improve it, not doing it for the money they hope to make.
Edit: I forgot to add also - a reputable breeder to me, isn't just someone with dogs with titles or AKC (or in local case, ANKC) registration either. There's a lot more involved and they'd have to prove themselves to earn my stamp of approval. Clearances, CERF, OFA, facility visit, and overall care. I'm surprise Ori and Jasmine's breeder didn't think me to be some sort of weird nosy person as I practically asked for everything but their personal birth certificates. But, when the Guide Dogs Association has them on their "go to" map and recommendations and the trainers even invest in several puppies each for themselves...well, I get convinced kind of quickly. Lol. I think they probably just sent me there as a last resort before I asked to move in to monitor them...