alt Hacker NewsOver-consumption? That doesn't follow. I sustain my family on Costco, going once a month or so, but have to feed four people, including two teenagers that consume way more than 2000 calories a day. You keep using the word "oversized", but that assumes the SUV, the fridge, the trolley are not suited for purpose. But they are!
I think what you're really critiquing is people who don't shop frequently, and therefore buy in bulk.
I think the poster is indeed criticizing bulk shopping. I would then to agree that shopping in bulk makes it easier to overprovision or to have things go to waste or being bought superfluously. I am also not sure about it being cheaper in total because my experience with bulk sellers is that they achieve their profit margins by their product mix, so selling you some cheap items as loss leaders or discount items and recouping on others that you buy at the same time. Doing weekly shopping trips at different supermarkets can counteract that by letting you buy more various promotional items.
Of course it comes down to how much personal time you then have to spend on shopping to drive your bill down.