Absolutely, though I know that some other places have said it's allowed as long as they're rescue animals, which I also agree with assuming they're given a bigger space to walk around and not kept in a box-sized window cubby.
There are so many animals in shelters and foster homes that need a loving, permanent home. I know everyone likes the idea of a cute little kitten or puppy but it would be nice if we could get away from that being the only "good" option.
There are also still lots of puppies and kittens at shelters. We adopted both of our dogs as puppies but one has behavioural issues (extremely timid and afraid of people - he's 9 now and still this way), and the other was born with cataracts and was almost completely blind (he had surgery a few years ago and now he can see perfectly!). Neither would have cut it in a pet store where the emphasis is on being cute and playful and fun, but they're still such wonderful companions and family members.
I find it incredibly rewarding to take in a less-than-perfect animal and show them love. And I find it very sad to see animals stuck in those tiny enclosures all day every day at the pet store, born and bred for that very purpose. I am all for redirecting interest and demand towards shelter animals, at the very least it might deter people from getting a pet solely on a whim because they see it at a store and think it's cute without realizing what's really involved in caring for a pet.