I would hope people aren't happy about it, but you must not be reading the thread if you somehow missed the glee that many have over the latest Nintendo failing.
The fact that you bring up Sega is ironic, because they brought out a bunch of amazing, varied games in the DC days... and then went bankrupt.
If the lesson is ultimately "amazing games aren't the key factor in determining success," I don't know why ANYBODY on this board would be happy, other than the console warriors and plants and so on.
You seem to be ignoring the biggest group: the ones that want Nintendo to succeed but would like it if their incredible games like Mario 3D World, Pikmin 3, and Wonderful 101 dictated that success, and not "doing what everyone else does."
Sometimes the most obvious reason is the answer, and that is: The Wii U has the best games to play, right now, and at the lowest price. What happened is the PS4/Xbone finally released and so they could stop stoking the fires of that hype machine and look back and say, hey, there's actually a lot of fun software on this Wii U thing.
The fact that you're trying to ascribe some hidden motives, like "pity" or "nostalgia" or whatever speaks more to your line of thinking than the reality of the situation.