Activists want to close down puppy mills because more often than not, they're horrible places for dogs. Lawmakers in California are working on legislation that would make it illegal for pet stores to buy dogs wholesale from commercial breeders. People can go directly to breeders to purchase a dog instead. Pet stores would still be able to sell rescued dogs from the shelter.
Many activists are pushing for this model for the buying and selling of dogs because it forces dog owners and breeders to take on a larger role in the process. Responsible breeders should be meeting with potential owners before placing a dog with them and owners should meet the breeders to see where their dog is coming from.
Commercial breeding exacerbates the worst tendencies of the market. More often than not at the expense of the dog's health and wellbeing. Puppy mills are cruel and unnecessary.
The American Kennel Club (AKC) opposes legislation against puppy mills because they say it's the wrong answer to a real problem. There are already standards dog breeders are held to. Instead of adding more laws, people should focus on enforcing the ones already on the books. Giving more resources to inspections and going after bad breeders would do more to solve the problem than just outright bans. Someone still needs to enforce the law.
The AKC says the number of dogs in a single breeding operation isn't the issue. A breeder can have 100 dogs in a single operation and it could be just fine. Another breeder could be dealing with only a few and raise them in horrid conditions. It all depends on the breeder. That's why more inspections and responsible sourcing is key to stopping puppy mills. A ban won't stop anything.
Besides, many commercial breeding operations aren't just raising dogs for pets. Service dogs are in huge demand as well and breeders are necessary to supply the animals.