I didn't realize the scope of the problem until I worked at a shelter.
When I was young, I thought I wanted to be a dog breeder at some point. I didn't think a thing of it, until I volunteered at the local shelter for about six months and saw how many pets are dumped, unwanted, sick and frightened. Entire litters of puppies and kittens euthanized. If this doesn't break your heart, you'd have to be made of stone.
I can't go into the shelter anymore. I simply can't go in there without bringing something home, and we already have a houseful.
People who think they want to breed their dog "because it has papers" or to let their child watch the "miracle of birth", or to make some money, or whatever, simply don't *see* the immensity of the problem--it's easy to look the other way, until you are smack dab in the middle of it. "Puppies are so cute and precious--how can it be wrong to bring them into the world, when they bring such joy? You must hate puppies!"
I notice that a lot of people here, breeders even, don't fully comprehend the issue, and continue to wonder if we aren't exaggerating the overpopulation problem. I can only guess they've never worked in a kill shelter and helped the guy from the rendering plant load dozens of frozen dead dog and cat bodies into the truck, or assisted with euthanizing perfectly friendly, healthy puppies that lick your face as you hold them for that final injection.
I'm not saying that responsible breeders have any fault or guilt in this situation. Why are pets considered disposable? Because there are so **** MANY of them. In our area it's Pit Bulls. Almost every Pit Bull I see on the street either has testicles or sagging teats. It's as though it's required to breed them, so people are constantly handing off puppies to people who don't really want them once they grow out of the "cute" phase. We have so many adolescent Pit Bulls in our shelter it would make your head spin. Why? Because there's a cuter, younger one in a box down at the Walmart for free. They are literally disposable dogs that you can use and throw away, because there'll be another one right around the corner when you tire of the first.