Putting apartments on top of big box stores seems like a perfectly fine thing to do wherever the stores are in urban or more populated areas. The only real problem here beyond the usual landlord-parasitism is if these start being handed out to Costco employees tied to their employment status (and even then if you're working retail your living situation is probably fucked when you lose your job anyway, so I'm not sure it even exasperates that problem all that much in hellworld).