The fact that they sell puppies and kittens from mills. It would be so much better if they adopted out animals. The dogs they sell are usually poor quality, anyway. I'd sooner adopt a mutt than pay hundreds of dollars for an inbred puppy from a mill.
Also, the Petland in my area sells common Domestic Short Hair kittens for $99. Do people realize how stupid that is? You can go to the shelter and adopt the same kind of kittens for $60, and adults for $40. Plus you save a life that way. Duh! But Petland is still in business because people buy into it. The staff there is a joke, too. Half of them have no clue what they're talking about, and the other half just tell you whatever they have to to make a sale.
I will say that most pet stores around here have really nice aquariums and their small animals are well cared for. There's even a shop that sells short-tailed possums, sugar gliders, and prairie dogs. The cages are always spotless and the animals are healthy. Nobody carries horse supplies, though! Our Petsmart used to carry Stateline Tack, but it went out of business years ago. It really sucks, because that was my go-to place. They had the best prices and a huge selection. I mean, they had everything
you need for a horse. Now I have to mail order almost everything.