You need the motion+ for several WiiU games as well (I think the Zelda game in Nintendoland needs it at least).
Ontopic: Because everyone will love shoving devices in their eyes for a quick gaming session.
No, not several, a few.
When you're involving the thousands of titles of both Wii and Wii U, a dozen games is not several, two dozen games is not several, three dozen games is not several, four dozen games is not several. And it actually matters if these games are of a quality people actually want to play. While many can agree people want to play Zelda, you have to come to the realization that what little games that do rely on Wiimotion+ are things like Nintendo Land, Carnival games, Spongebob games. To real gamers those games don't even count. From 2009, all the way up till 2015, theres maybe going to be 40 games stretching across two console generations, only half-dozen of which are even worth remembering the names for.
And just like I said before, Nintendo made Wii Motion + for one game, built it's reputation up to a point like it was going to be some sort of new standard for Wii, but ultimately only made a few games after Wii Sports resort that take advantage of Motion+, fewer games that actually require it.
In the last 5 years of Motion+, it's only barely made itself more useful than the Balance Board, Wiispeak, or the N64 Expansion pak. Here's a history of Wii Motion+
http://en.wikipedia.org/wiki/List_of_games_that_support_Wii_MotionPlus
^And yeah, it really is that sad. So I reword your "several" to "only a few" because we're dealing with not one, but two systems in Wii Motion+'s almost 5 years history, in a sea of hundreds to thousands of possible titles.
I'd just like to remind that Wii's best peripheral is still mostly an unsupported failure, so theres no hope for Nintendo Augmented Reality contacts, because lets face it, the contacts would probably cost more than the Wii U itself to cover the insane R&D budget to develop it to the point of surpassing limitations of electronics. And it would go unnoticed, unappreciated, and unsupported. AND AND AND, this isn't even addressing comfort issues, storage, loss-prevention, battery life, security, blah blah blah.
I sure as hell aren't putting scratchy $1000 contacts on my eyeballs just to play the latest Wii U Sports adapted to use such technology..