I hate the idea of subsidizing any pet shop that does not treat its animals well. That's one reason I won't buy from my local pet store. They keep some of their animals in deplorable situations. The rats look like they're ready to die.
I would never buy a dog from a puppy mill for the same reason. I don't want to contribute to that sort of cruelty. Maybe one day, if everyone felt the same, these people would go out of business.