A blanket statement that buying a purebred dog is unethical is ridiculous, I'm sorry. There are many many many reasons to buy a purebred, and it is possible to do it ethically and through good breeders.
Hell, my rescue dog WAS a purebred!
People are getting so weird about dogs, if you aren’t “rescuing” a dog from the pound they think you ought to pay penance for the privilege of owning one in some other way or something.
I remember we looked at a cat shelter in NYC when we were looking for a cat and they wanted like a credit check and two personal references or something and I thought, "This cannot possibly be justified."
