I agree with a lot of your points, but I don't think Nintendo is necessarily in trouble unless they fail to adjust. The market has outright rejected the Wii U and is starting to reject the 3DS, so 2015 will be pivotal to see if they are going to adjust or simply sell to their industry niche. They might be fine either way, but their niche has been steadily eroding since the SNES and is now at a low.
I think that the Wii market still exists, as naiive as that may sound. However, its full of people who are looking for cheap multimedia machines that do everything well. And no manufacturer, not even Google or Apple, has cracked that balance yet. I think it's too much for Nintendo to take on again, as they are absolute dinosaurs when it comes to services and multimedia. If they introduce a product like that it would probably take the most resources from them than any console they ever did to overhaul their design and R&D line of thought.
As far as PS4 v XOne, its clear IMO that the XOne is just now reaching a price point that's appropriate for its perception. The word that it's a 'little' weaker than the PS4 and may not get the foreign games has pretty much become standard knowledge. The Call of Duty/Sports/Shooter gamer typically does not care about stuff like that, but with both consoles being the same price they would go with the slightly better experience. Now, with the XOne cheaper, it may have been enough to sway those casual/fence sitters that the difference between the two systems is not as important as saving $50
Plus the market was hungry for next gen. What better way to enter next gen than at $329 with 4 games?