I think Nintendo puts out great product. They are definitely my 2nd favorite of the big 3 (granted, not saying much since I despise MS but I really do like Nintendo a lot). And I thought the Wii U was a great piece of hardware for the most part, but traded mine in last year because I wasn't using it at all (no games at the time that interested me) and the trade in value was just too high for me to turn down at the time - not to mention I expect a further price drop in the not too distant future.
That said, I think since the Wii they've started relying on gimmicks too much. The motion control fad sold a ton of systems for them, and it seems that's made them believe that every system they put out now has to have a new gimmick to spark off a new craze. They don't. The Gamecube is still my favorite Nintendo system, and IMO it's the last time they were trying to compete head-to-head on the home console hardware front (as in specs on par or better than their competition, going after third party AAA titles, etc.). The 3DS is a fantastic system, I wouldn't part with it (or my Vita, for that matter). But the 3D is completely irrelevant. I haven't had it on in ages, because frankly not only is it pointless but it gives me a headache. My wife tried using my 3DS recently because I picked a game up for her. A few days later she tells me "I don't like the 3DS, even with the 3D off it still looks funny & hurts my eyes." She didn't realize the slider has to click down to completely turn the effect off, and once I showed her that she was fine.
The Wii U's touchpad isn't that bad; I can actually see some practical uses for it. But at the same time, it isn't necessary. If they had gone the touchpad route, or at the very least made it an optional accessory and not something packed in with the system, then they most likely could have shaved about $100 off the price of the system and would be sitting in a much better position now. $250 puts them close enough in price to the PS4 to make people think "For another $150 I can just go that route, it seems to have more games coming for it anyway and I'll probably end up with one at some point regardless...". If the Wii U was $150, it would be in a class by itself and its technical deficiencies wouldn't be called into question nearly as much. Because heck, it still looks fantastic and for $150 you could have access to Mario, Zelda, etc. - why not? It's an impulse buy at that point.
So don't misread any of this, I want Nintendo to succeed and I want them to stay relevant in the console market for years to come. But in order for that to happen, they're going to have to stop relying on gimmicks and instead focus on what they're best at - making AAA games that appeal to all ages.