I think there is some merit to the practice from a product design standpoint, though - the commonly cited example of a door with such ambiguous design that it n

I think there is some merit to the practice from a product design standpoint, though - the commonly cited example of a door with such ambiguous design that it needs a "push" or "pull" sign seems to apply here. Sure, we could leave the door as a blank surface with no hints (design or signs or otherwise) and let people decide whether to try and push or pull on their own, but doesn't that just waste everyone's time? A paternalistic approach isn't necessarily a bad thing if you're being guided through decisions with the benefit of someone else's experience. It helps avoid spending mental effort on decisions which don't matter as much, so utmost attention can be given to those which do.