I think the problem got worse under Wii. GCN had decent support. But under the Wii Nintendo was one of the only developers making good games for the console.
i have said this time & again, Nintendo need to break this cycle, i have had every Nintendo console (not all handhelds) since the NES but every generation Mario, Zelda, Metroid is rolled out again, but this time it is in 3D or it is 64bit or you can control it by waving your arms about, you can play with a touch screen, the issue is that it is basically the same game, but with better graphics & a new user Interface, this in a way is no different to the Call of Duty games that all Nintendo (apparent fans) rail against for being rubbish.
people are getting tired of the same thing now, i know i am, the thing with the WiiU is that Nintendo said they had big third party support, but they clearly don't & they MUST of know this because the games would of been already being made before the WiiU launched, Nintendo really have to start getting a grip & also moving with the times.
it is hard to understand what Nintendo were thinking of with the WiiU because they knew the issues they had with third party support, they knew there would be the X720 & PS4 released within a year or two of the WiiU launch, they must of has a idea of the power that the X720 & PS4 would have, but what seems to of happened is that the WiiU is seeming underpowered (not able to run the engines that will power games on the X720 & PS4) but also created developing issues like the PS3 had when it was launched.