You (general) being a breeder with a waiting list and homes for puppies who go to serious breed enthusiasts is wonderful. You are not contributing to the problem.
You(general) being a breeder who has multiple litters a year with no idea who will end up buying these puppies once they are on the ground is not wonderful. You are contributing to the problem.
Before anyone quotes me and writes several paragraphs about how they have a waiting list and they do DOG SPORTS- stop. We have established that on this forum, we have many wonderful breeders who breed purpose bred dogs for people who want purpose bred dogs for purposeful dog sports. On this forum, we also have a large portion of people who do dog sports and need purpose bred dogs; I suppose it is because of our long relationships of using horses for work.
However, there are many, many people in this country who do not want a dog to do a dog sport, nor are they great enthusiasts of a well bred insert-breed-here and will get one from a good breeder come hell or high water. In fact, the general American public does not even train their dog. Shocking to some here, I know. But the general American public is not COTH. They want a dog to play in the backyard with and clean up the floor when they drop something. This requirement can be filled by any dog. In this way, a dog is a dog.
HOWEVER.
A dog is not a dog when you need it to do something specific, like a dog sport. So don’t tell me about how you need your dog to do agility so you must have an insert-breed-here. MOST PEOPLE DON’T NEED A DOG TO DO SOMETHING SPECIFIC. I am not saying a Maltese and a German Shepherd are the same, though, and suitability should of course be considered, but for most people, a rescue dog fits the bill just as well as a purebred.
Purebred Labs, for example. I work in a vet clinic. Labs are the most common dog where I am (which is why I’m using them as an example, nothing against Lab people). There are people who bring in their 8 week old Lab puppy that they got from a breeder. They have kids, usually around 8 or 9, who begged for a puppy. Do they have any big plans for this puppy? No, it is a family dog. This puppy will grow up and come in for its regular wellness visits and every time it will pull on the leash until it chokes, jump on everyone it sees, wind people up in its flexi-leash, and refuse to sit on the scale despite the owner yelling, “Sit, Buddy, sit!” THIS is the general American public. Do they need a purebred Lab? No. They could have gotten any dog from a shelter. More than likely, this Lab from a breeder was a backyard breeder selling puppies for $400. A shelter dog would have been the same price or cheaper, just as suitable, and would have had the added benefit of saving a dog from euthanasia. The shelter probably has a dog that looks and acts a lot like their purebred Lab, if that type is what they’re going for.
Shelters have everything. Here in the south, we get a lot of pit bulls, of course, but also a lot of beagles and hounds that won’t hunt. We also get labs, maltese, chihuahuas, shih-tzus, papillons, GSDs, border collies, basenjis, etc. Some are purebred. Most have some kind of mix. But for most people, they don’t need a purebred. A mix will suit them just fine. They are temperament tested, vaccinated, usually microchipped, and spayed/neutered. And since the vast majority of them are going to receive no training at all, they don’t even need to be smart, just sweet 
Sorry for the rant, but all the breeders on here are getting into a tizzy that us rescue people think that a dog is just a dog but they need to do DOG SPORTS so they need a purpose bred dog. That is totally fine for you and people like you. But the general public does NOT need a purpose bred dog.
