I think the problem is (yet again) Nintendo fans set their expectations way too high. I remember before the Wii launched a lot of Nintendo fans pushing the line that you wouldn't be able to notice a difference in graphics between Wii and 360/PS3, the main difference would be one would run in HD and that's it. And that we'd get all these amazing experiences with motion control like a lightsaber game and tons of great FPS games and so on.
And that developers would abandon PS3/360 because HD development was too costly and making Wii games would be cheaper, etc. etc. etc.
With Wii U again, I think some of the hyperbole got out of control. Remember this?
Sony fans tend to be happy because Sony more or less simply gives them what they want -- relatively bleeding edge tech, good online, embracing new trends in gaming, lots of "grown up" IP, and most importantly a high variety of games from themselves and third party partners.
Sony's biggest screw up was the $600 PS3, but within a year you could get a 40GB PS3 for $399.99, so that was largely a short lived complaint.
Nintendo fans are constantly put into a bind because we love Nintendo games, but are forced to endure some incredibly archaic hardware policies to get those games -- paying top dollar for outdated hardware, having to "buy in" to the philosophy of each hardware being now tied to a novelty (3D screen! 2D screen controller!) rather than the NES/SNES/N64/GCN days, suffering with a horrible OS and online policies (no account based system), and the perpetual situation of piss poor third party support ... eventually begins to grate on a consumer.
