I actually disagree strongly with this assessment for people that have gradually grown distant from Nintendo over the past few years (or decade) as a result of "growing up"
I can still appreciate a Nintendo game that has high production values, that sets the bar high, that innovates, and that distinguishes itself far above its peers.
Titles like Mario Galaxy come to mind. These are "AAA" experiences just as much as you will find on next-gen systems when you're picking up the next Naughty Dog game, for instance (in my mind).
Problem is, Nintendo has actively gone against the AAA strategy for the better part of a decade or more. It's rare to see something like Metroid or Mario being given massive production values. And it seems like we'll never see a return to form for ambitious development from Nintendo whom, at one time, managed to shock the world with groundbreaking content like Mario 64 and Zelda: OoT.
They have fallen so behind when it comes to AAA development, like many Japanese studios, that it almost feels like they'll never be able to compete again. Instead of Mario 64, Mario Galaxy, or Zelda: OoT, we get derivative, stale, low-budget productions that are recycled ad-nauseum across their platforms. As a "grown up" gamer, I can appreciate something like Mario Galaxy....but when I see the New Super Mario Bros games and even the new Super Mario 3D world, it does not excite me whatsoever. There's a massive divide in quality of production that Nintendo seldom chases anymore.
Nintendo of today isn't nearly as exciting as they used to be, and I fear that their complacency with regards to the Wii's success has set them up for a disastrous failure for the long-term health of their internal studios.