There is such a thing as being young at heart, but I think you need to make a distinction between fans and loyalists. A gamer can be a fan of games on the platform, and yet play on multiple platforms. While a loyalist plays on that platform exclusively. The reality is that Nintendo doesn't have a lot of those, and fewer still hardcore loyalists. The first group is most assuredly casual in nature. While the latter is probably on the older side. They started with Nintendo a long time ago, and they have become just plain habituated to the brand.
In the case of the last group you could say there is a misconception, but not much of one. They may be old, but they are actually playing games geared towards a younger audience, or at least not geared to anyone specifically. I think most of the misconceptions about games come expressly out of that group. They still think in terms of the rivalry between Nintendo and Sega. They very often automatically assume that Mature gaming is about blood and gore. Sex and mindless violence. You tell them Nintendo should get more mature games, and their brains go right there.
Yes some people are still litigating a argument today that they made when they were eight or nine years old, and they just never stopped to reconsider that belief. So a lot of older gamers do in fact come across as if they are eight or nine years old, because they are making arguments from that point of view. That isn't fair to say however that it is fair to generalize a whole fan base no matter where they fall on the spectrum. It is however understandable that it happens since those that haven't moved a inch since they were eight or nine years old. Are usually the loudest voices in the chorus.







