If you ask me, the argument that this conjecture is a failure to understand what Nintendo does. They use the same characters, but that's where the nostalgia ends. But even that is dubious: would you ever argue that an adaptation of Shakespeare is trying to use nostalgia to grip its audience? or that the 8th season of a TV show is resorting to nostalgia to keep its audience around?
This guy is one of the best Donkey Kong players in the world, and not because he's nostalgic.
No, Nintendo is about so much more than nostalgia. For me at least, nostalgia plays little to no part in my continued obsession with their stuff. Quite the opposite, in fact. The reason I'll always be with them is because their stuff is always new: new challenges, new skills to develop, new Mario to play.
I'm playing Super Mario 3D World right now, and it's so different from all the other Mario games it doesn't feel nostalgic at all. Mario isn't a series as much as it's a genre: like reggae, or blues. When you listen to one of those styles, you expect certain things: instruments, tempo, style of play, subject matter.... If you're a fan and someone makes a good blues album you'll listen to it. There's no nostalgia, it's a new thing. The notes are different. The people who made it are different. There's a different soul, a different message.
Mario is the same way: we expect certain colours, enemies, and characters, but the notes are all different, and the instruments are evolving. In this case, 3D World is to original generation Mario platformers as Led Zeppelin is to Muddy Waters. You think Nintendo is one big machine with exactly the same parts all the time? The team that made New Super Mario Bros. U is not the same one which made Super Mario 3D World. They're different people, they have different things to say. It's not a story thing either (obv). It's about challenges. The Japanese are all about having skills: bushido is a perfect example. He who is great with a sword will have great glory & honour. Nintendo games are tools to train players, to challenge them, and to make them feel honourable!
So no, I don't play Mario because it reminds me of the good old days. I hate thinking about the past. Hell, I think Mario's a dick who deserves to be imprisoned.
I am a Mario master. That's why I play Mario games.