Nintendo's development model is actually one that's user-focused instead of product-focused. They have been known to make drastic changes in a game simply based on what their test focus groups have done (for example, Mario Kart Wii's motorbike controls were entirely revamped when they noticed that people kept trying to use the Wii Wheel like it was a set of handlebars).
This user focus means they put out products which will please the vast majority of potential customers, and is why they have no problem selling untold millions of copies. The only thing one could refer to as a "downside" to this process is that it tends to alienate those users who are ready to move upstream to more complex titles. And even there, they've got studios making upstream games. About the only crowd lost to them is the extreme upstream gamers who prefer games that are more work than game.
Sky Render - Sanity is for the weak.
