Because they are STUPID and having nothing else to do with their money except line the pockets of the breeders instead of offering a home to a pet that is on death row.
I'm sorry but that statement offends me. Just because somebody chose to get an animal from a breeder does not make them STUPID necessarily.

I didn't get Nebo from a great breeder. There's nothing I can do about that now. I love my dog and that's that!

I've said many times that my next dog will be from a shelter or rescue. I can't predict the future, I don't know what will happen or when I will ever be able to get another dog. All I know is that is what I'd like to do, and that's what I'll try to do. I've found many on petfinder and rescue group websites I've fallen in love with. There's one right now I'd drive down to Texas and get if I was able to!

But no matter what I do, I don't think it's anyones right to assume that I (or anyone else) don't care about homeless pets because they got one from a breeder.

Now I do definitely agree that sometimes it's stupid for someone to say they couldn't find the right one in a shelter...as many dogs go in and out of shelters, rescue groups, etc. so it is a time process. Just because you don't find the perfect one the first time you visit doesn't mean the perfect one won't arrive.