So it's widely known as a fact that many Nintendo games have ridiculous legs. But here's the question that no one really bother to ask...why is this so?

[platformmaster918]

Because they don't come out with a sequel for the system. If you want 2d Mario on Wii, you have only 1 option. So they keep it on the eye level shelf at full price. 3d Mario only had one game per gen until this one. 2d Mario the last 4 systems its come out on has been 1 per system. Same with Zelda except for the hybrid TP. MK has always been one per system same with Smash Bros. People want those franchises on their system and there's only one place to get them. Sony has only done this once that I can remember and that's with GT5 to a similar effect. Their games usually have a strong party focus for lasting value as well, at least that's why I get them (on ebay or Amazon at drastically reduced prices from the store). Zelda and 3d Mario are great SP experiences, but Smash, MK, and 2D Mario are great local co-op games with that lasting fun factor. Same with Goldeneye back in the day.