I agree that shelter pets should be a first option, but I don't think blaming the breeders is fair or constructive. Like it or not, there's a market and the ethical ones are meeting it. Our culture needs to change so that people who want to adopt pets recognize they don't need to spend $500 for the perfect pug when there are plenty of lovable mutts who need a good home. I don't know how this happens except at an individual level.
Don't you think it's unlikely that a grown adult doesn't realize that they can go to the pound and adopt a pet?
The only explanation is that, being aware of their options and hopefully having done some research, they've made a specific decision to buy a specific breed.
I'm not anti-mutt or anti-pound-dog. We did a lot of research before bringing a pet into our home, and decided to buy a specific breed. Our research paid off, and we're thrilled with our dog. This seems much more responsible than grabbing whatever is available at the pound and then determining that it's not the right pet for our family.
What the public could probably use a little more education on is the need to spay/neuter their pets.
Another point is that an ethical breeder will always take a dog back for any reason, whether health issues, temperament issues, or the owners just can't keep the dog for whatever reason. Responsible breeders have a pretty hefty contract that you sign - with limited registration and a neuter-spay agreement, and a first refusal provision.
Those folks aren't the problem.