That certainly puts things in a clearer context. If people are doing that? Then I can see how Walmart might say "Thanks, but no thanks" because people are abusing the return policy. If you see the same customer doing this habitually, that kind of extreme response becomes that much more understandable.
It's really not much different from how things have worked at brick & mortar stores regarding returns. I remember some Hot Wheels guys who were basically banned from Toys R Us because they would buy loads of Hot Wheels and then return the ones they couldn't flip. They had done this often enough that they got flagged in the TRU computer system. I think they could still buy from the store using cash, but as for returns? It wasn't happening. Situations like that are a big part of why stores began asking for ID when processing returns.