The one and only crested gecko I bought from Petco was a non-eater. Feeding him by hand was a huge pain but was required for a few months. I had to work hard to finally get him to eat CGD from his food dish, and he absolutely refuses crickets.

I don't regret the purchase though, he's absolutely beautiful

Petsmart, all I've ever bought from them is supplies.

The fact is that their quality of care isn't as good as if it was in a good home. They bank on the fact that their animals will sell fast enough that they don't need to provide the best care. You see animals at both petsmart and petco having health problems generally because they haven't sold for an extended period of time and begin to suffer from less than optimum conditions.

Also, it's not exactly challenging to keep a corn snake healthy, I'd say that their corn snakes are just fine to purchase for the most part simply because of how hardy they are.