While the system isn't selling well, one thing that's really killing the system's potential future sales is the fanbase. Just take a look at the sales numbers for Wii U games.
http://www.vgchartz.com/gamedb/?name...=0&results=200
It's been out for about three months, and the 11th top selling game, Disney Epic Mickey 2 sold 90,000. Just about all the games below that are ports, sure, but most of the people who own a Wii U, I'm betting don't have a PS3 or 360. There are those that do, but I'm thinking the majority probably don't. If those people don't show third party support it's just telling developers that their games aren't going to sell well on the system. I'm sure this is the reason Ubisoft went multiconsole with Rayman Legends and EA didn't announce Wii U versions of their future sports titles. There have been a lot of sales for Wii U games so there's no excuse. Nintendo Land doesn't count because most of the sales there are because it's a pack in for the deluxe model, but if you go by sales and see how much New Super Mario Bros U sold compared to everything else, even compared to Zombie U which is third place and sold 330,000, most Nintendo fans are telling third party developers that they don't want anything other than first party Nintendo games.
People are complaining about not receiving future releases or Ubisoft pulling a dick move by pushing back the release date to make it a simultaneous release, but there's a clear reason why if you look at what games are selling and what games aren't.
*edit*
Edited time frame Wii U has been out.