This seems like a very narrow niche, shoppers who order en route to a store already. If you order a little while ahead and wait for it to be ready, then you're fine. If you don't order ahead and just shop when you get there, no issue.
Most other stores do the same thing BTW. They need time to get your order, process it, have an employee go grab it, confirm the order and set it aside for pickup. In busy stores, this can take some time. If I'm ordering things from REI or Best Buy, for example, it can often take either a few minutes or a few hours for my order to be ready.