Pet stores source their hams from rodent mills, which horribly mistreat hamsters. Pet stores, too, mistreat their hamsters, there are many examples but here is one: https://mothership.sg/2019/08/hamster-sandwiched-cage-pet-lovers-centre/

Unsafe products that are sold cause many unwitting owners to buy them, thus leading to terrible care of hamsters, and high risk of injury and health issues. For example, hamster balls have a lack of ventilation and pose a risk of trapping toes and limbs, mineral chews are extremely bad for hamsters, the burp food mixes have no nutrition value, and small wheels cause bent backs. Then of course, tiny hamster cages cause a LOT of stress and plenty of issues such as bar biting, monkey barring, etc. Unfortunately to the average hamster owner, all of these seem completely normal and are products commonly used. 

Also, pet store employees have NO experience or knowledge in proper care and will often recommend or even press customers to buy unsafe products such as tiny cages, scented sand, etc.

I seek to change that and I hope this situation will improve.