Because of the huge success of the 360 and PS3 and how they defined the current mainstream market, many gamers are now invested in the ecosystems Sony & MS have created.
I think it's more risky than ever to release products that steer away from the norm on the home console market, consumers generally want a console they know will play the latest big commercial releases, and they don't want to have to buy 2.
However, I think the market is still very much there for those that want something different, but getting and retaining the attention of that market is very difficult.
Mario Galaxy, Mario Bros Wii. Mario Kart Wii, Smash Bros Brawl etc all sold very well last gen on the Wii (especially MK). I'd like to see more original IP's from Nintendo, sure, but I don't agree that the games are really the biggest issue here.
Nintendo are struggling to get consumers to trust in their home console platform, and yeah, maybe the price plays a part in that. The 3DS struggled at first, but they turned that around.
If you know anyone that works in games retail, ask them how well they think those enquiring to buy a Wii U understand the product. The console is often perceived as a 'Wii Upgrade' for example... which is not good and largely Nintendo's fault.
I've found even friends and colleagues that actually play games have similar views of the console. e.g. "I'm interested in Bayonetta 2, but i'm not sure how they'll make it work on low spec Wii hardware". I go on to explain that the Wii U is basically a 360/PS3 with more RAM and an slightly upgraded GFX card and they are genuinely surprised.
I don't think anyone is expecting MK8 to make the Wii U a huge success(if it does it'll make history!), but it'll certainly boost momentum and should allow Nintendo to start making notable profits.. I hope it works out well for them, but I'll continue to enjoy the console regardless.
I was generalizing by saying it was OK to not like a -good- game, there are plenty of people that express their dislike for certain games, or games with particular themes, no matter the platform.