Nintendo making a hybrid handheld would bring the success of the handheld to the tv, like you said, thier handheld sector is gold, this would be spreading that wealth.
3rd parties are already on board with the handheld. Sony is the only other handheld and Nintendo is getting squeezed out of the traditional console, so a hybrid would be a type of drastic measure that would make sense.
And it still leaves the door open for releasing a traditional console to replace the "TVbox" down the line, knowing that a majority of gamers already have the controllers in hand, and that additional controller to pack in would be much cheaper to produce by then.
based on your own argument above, I think the Hybrid handled/console makes more sense. Nintendo would own the whole handheld market while also keeping their got in the door of the console market at the same time as strengthening their smart box app game.
They would unify their game development efforts, most 3rd parties are already down with Nintendo the handheld arena, more resources can be put toward VC , ware, apps, dlc, cloud, more games, assisting other developers, establishing more partnerships/3rd parties, etc etc.
It just makes so much sense that I honestly think Nintendo might do what you suggested instead.... :/ how depressing. Why do you have to be this way Nintendo!!?