I don't think that's hyperbole either. It's a nutritionally complete food that's fairly easy to grow, to ship, and it holds up for a very long time without refrigeration.
The only place I've been lucky to visit where I didn't see potatoes was Costa Rica. Rice and black beans all day every day. Indians seem to like them very well. I don't know about other southeast Asian countries, China, or Japan but it seems unlikely they eat so much.