You might think that Nintendo, beleaguered by falling revenues, minuscule profit and the almost-but-not-quite-failed launch of the Wii U, already has enough problems to worry about. And you would be wrong, as Nintendo itself set out to demonstrate last week by going out of its way to alienate a bunch of its fans on YouTube. The fans in question make YouTube "playthrough" videos about, well, video games — features that combine elements of commentary, review, tutorial and walk-through. Some of these commentators reach millions of subscribers, and many support themselves in full or in part by…


