Nowhere does it say that pets4homes were responsible here just that the puppies were advertised there. There are very clear guidelines on buying puppies on the pets4homes website wrt ensuring that you see the parents and conditions etc, and while I wouldn't personally buy a puppy advertised there I do know people who have and who haven't had negative experiences.
TBH though, while these women were absolutely responsible for the conditions they kept their dogs in, surely the people who bought these puppies have to take some responsibility as well? If you turn up to pick up a puppy and see it in those kinds of conditions you surely don't walk away with it. Or if you're offered the opportunity to collect your puppy from the services on the m4 or the like then you don't go there.
Puppy farming absolutely has to be outlawed but the people buying puppies in these conditions are a huge part of the problem as they're prepared to pay £££ for puppies bred in awful conditions and are fuelling a supply chain with their demand.
Personally I believe that breeding animals for profit should be made illegal, you would shut down the puppy farm trade in one swift move if you did that.