If Nintendo had made the apps included worth using for 10s of hours then surely that would be to the detriment of the light duty cardboard used? The cardboard would wear out quickly and people would complain they couldn't use the apps anymore. I suspect the apps were designed to be a short lived experience for that reason. They could have used corrugated plastic card instead of normal cardboard in order to make a more long life product but they didn't. If they continue with this concept perhaps that will be a future revision of the product.
If you like the concept why not just make something out of cardboard yourself. Come up with a design and then build it with scrap cardboard. A lot cheaper and a lot more satisfying I would of thought. There is plenty of inspiration on the web. It will then be your own creation. Better still making something that can be used with wood or metal.
