Eh. The problem isn't that Nintendo is innovative, but that it's bad. I've played the Wii, and there's not a game on it that I didn't think would have been better on the gamecube. Innovation by itself should be encouraged, but if the innovation isn't good it's not magically better than an less innovative game that is fun.
No one "blames" Nintendo for being innovative, or blames Mirror's Edge for being different. We blame them for sucking. Mirror's Edge had so much wrong with it (including unintuitive controls, poorly designed levels, and a rejection of the very things it should have been) that unless the last screen of the game cured several types of cancer, or that all of the running in the game translated to real-world weight loss, it wouldn't have been worth playing past the first few levels. The Wii was intended to be true motion control, but the controls are so finicky most of the time that it's easier to just plug in a normal controller. We're finally getting a 1-to-1 attachment, years too late. And aside from the motion tracking, everything else is basically "use the wiimote like the old duck-hunt gun".
Throw in the shoehorning of wii features (or DS features) into basically every game, and it becomes really frustrating. Even without the shouting into your DS for Phantom Hourglass, you still have a fidgety wiimote feature in almost every wii game I've played, or a crappy DS feature. Bold effort, I accept, but they should have said after launch "okay, here's what worked about the wiimote: the motion control (sometimes), and the feeling of interactivity. Now let's get rid of the point and click crap, and see where we are)". Instead, they seemed to say "everything works great, let's make sure to put it into every game we can. And no need to make the point and click part work, it's fine if the cursor jumps and twitches since the little pointer strip is so tiny".
I do agree that one can't claim that Nintendo "betrayed" anyone, but the change in its target fanbase is somewhat jarring. All the way back to the SNES, they still had games that appealed to an older demographic. Smarter, funnier, more difficult, games. Super Mario RPG, Chrono Trigger, Link to the Past. On the N64: Goldeneye, Perfect Dark, Ocarina of Time. Even through the days of the Gamecube, they had games for both sides: Fire Emblem, Metal Gear Solid, Phantasy Star Online. But, now think about the Wii. Where's the balance? They've got SSBB, but there are plenty of people (myself included) who see most fighting games as inherently simplistic party games. Mario Party/Tennis/Kart/Golf/Underwater Basket Weaving? Sure, Paper Mario is nice (but not as nice), and even Fire Emblem is hamstrung by the crappy wii controls (same with Mario Galaxy and Twilight Princess).
So, it's not a feeling that Nintendo should mature with us, but the feeling that where they once had something to offer even a more mature demographic, they've become so invested in mining for coins from the young and elderly. Nintendo was never particularly immature until they decided that the best money was in crappy casual games (and in allowing any bedroom programmer to release terrible shovelware).