Why does Nintendo limit how much of certain games that you can enjoy each day?

One of the things that really nags at me about the 3DS is how I have to keep going back to the included games after either a period of time, after earning some more coins, or whatever, to be able to fully enjoy them. I’m specifically thinking about the limit on how many coins I can earn in one day for walking. I took a fairly short walk to the mall, around the stores, and home. I already maxed out my coins for the day and had only walked around for an hour. This earned me the right to hire five wandering heroes in Save  Mii, but what if I was ambitious and wanted to get a little further in that title? Why shouldn’t I be able to head back out for another walk just so I could hire some more kitties to fight ghosts? You can apply this same rant to earning coins to unlock more AR Games.

The first time I experienced something like this was with Master Of Illusion. You weren’t allowed to dive in and spend hours on hours learning magic trick after magic trick; the title required you to come back another day to learn new tricks. Something like Animal Crossing could be blamed for a similar tactic, but at least with that you feel like time is actually passing in a world created to entertain you, rather than following some arbitrary rule of how much will be revealed to you in any single day. Another title that suffered from limited content per day was Personal Trainer: Walking. It was another well-produced, first-party Nintendo release that didn’t have much to offer for a single sitting; you had to come back the next day to unlock another feature of the software.

It all leaves me feeling like I’m missing out on some social aspect of Japanese culture that might make this sort of thing okay, or that it’s a tactic to stretch the longevity of some extremely fun and cute games. Anyone else ever notice this or have more examples?