Seems like nintendo has some bad karma... Or the wheel of fortune has been swaying against them... But for any time on the bottom of the wheel, it is always sure to turn.
I say their situation is due to lack of innovation and progress and gameplay, and resting on their laurels. The universe is telling nintendo to move forward with new ips and gameplay ideas, but they are too busy focusing on what was succesful before.
They always trying something new and different with their consoles, and almost every Nintendo game (expect NSMB) have more new gameplay ideas and progress than majority of other games in industry.
That's a reason why Nintendo games are still top quality great games.