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?

[savisn]

My guess is that the evergreen titles appeal to a broad base that often includes that always underestimated "casual" segment. Every year some few million kids turns 8 and can now handle more advanced game mechanics. This segment doesn't care if Mario Galaxy is 2 years old or 5 years old. If it looks fun and appeals to both parents and kids it's gold.

Zelda is a bit above that level to where kids are picking their own games and are far more interested in games that are the new thing all their friends play. FE is much more for the high school and up crowd that would enjoy strategy and this demographic is likely to either get stuff when it releases or not at all