They can often be ignored, but they're not actually bullshit, they're just not for you. They're for the people who stock the shelves. If a product is past it's sell-by date, it gets tossed whether it's bad or not (it's usually not), and it is more to do with keeping a steady flow of inventory and keeping upstream systems working smoothly.

The (quite significant) loss of good food is acceptable to the seller because it keeps the incoming product fresh and consistent, which maintains their brand, and keeps their suppliers happy and willing to work with them. I understand why companies do it but it wastes massive amounts of perfectly good food and it's a genuine tragedy.