What's the point of no return for WiiU?

[Dream_While_Awake]

Max King of the Wild said:

Wii U needs to reach 14m by the end of 2014 to have a chance... (hint... those are gamecube level sales).

Why does it have to reach GC level by the end of the year to still have a chance? 

It'll still outsell the GC in the long-run.