The point is that they obviously weren't doing something right. If they don't fix that, their bucket is going to start filling.
In addition to what Jakyl said you have to remember that the Wii is at the end of its lifecycle and has crazy market share that there aren't many people left in the last year who wanted a Wii and didn't have one (which is inevitable with any system). So it brought in less revenue than any prior year. This is combined with high R&D costs attributed to the creation and design of the Wii U means they are going to lose money.
As an accountant I am not at all worried about a big loss in a transition year. It happens. Every company loses money eventually; it is inevitable. If they don't then they are cooking the books (in which case they are losing money they are just hiding it)
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(Maniac64 at work)
All the proteins, vitamins, and carbs of your grandma's best turkey dinner, plus 15% alcohol.