I agree with some of the OP's points but I have a different prediction for how things might one day progress once graphics are no longer a thing.
It's a simple fact that Sony and Microsoft have put a lot of their eggs in the basket of "our system delivers the best possible graphics" whereas Nintendo hasn't invested any amount of their brand into delivering industry-leading graphics since the GCN days. It also makes sense that we are starting to approach a glass-ceiling for delivering better graphics as the improvements are becoming less and less noticeable with each generation. Sony and Microsoft have the most to lose from this glass-ceiling as this will eventually require them to reinvent their current model, whereas Nintendo will likely be unaffected by this particular change.
Now that's not to say that people are just going to drop Sony and Microsoft and all run back to Nintendo. I actually think that it is more likely that the graphical-ceiling will be one contributor to a much bigger problem, that is: increased gamer apathy where more people gradually move to the casual-friendly, low-commitment games that they can play on their smartphones or similar devices. The console wars will be no more and harcore gaming will become more and more niche. Nintendo actually has their own stake in this problem because while they are not fighting the graphics wars anymore they are still very much about providing a hardcore gaming experience and the type of low-commitment gaming that we see on smartphones is just as much a threat to Nintendo as to Sony and Microsoft.
No, Nintendo can't hope to get back in the game by waiting for Sony and Microsoft to hypothetically self-destruct. What they can do is make the NX a successful console and win back market-share the old fashion way in the short-term: this well help them to be in a much better position when the bigger challenges come down the road.
