Your Nintendo ID is locked to the Wii U
Not able to be transferred or moved yet
This also means that if your console dies, so does your Nintendo Network ID. If your Wii U is stolen from your house or apartment, tough luck, ‘cause you also lost your Nintendo Network ID. If you decide to sell your Wii U, then the Network ID is tied to that unit and goes with it, even if you wipe it, because it is tied to the console. And now you will also not be logging into your Network ID on your friend’s Wii U.
Nintendo is aware of the issue and admits that in the future you will be able to use your Nintendo Network Account on other devices, such as PCs. We would also suspect that Nintendo Network IDs will be able to be moved at some point in the future, because consoles break down and people are going to want to move their account to their new Wii U and not have to create a new account.
As for why this happened… only Nintendo knows. We have to think that it is high on their agenda to fix because it will be a very bad black eye for the console right out of the gate. If you are under 18, you need a parent with a credit card; and now you are not able to move the account off the unit it is created on, even if you have a good reason to do so or need to recover it on a new system. Yeah, if we were Nintendo we would surely make this a top priority fix and get a team working on this pronto.