I don't necessarily agree with the direction Nintendo is taking their company in terms of their console, but I understand it; it's a sound marketing strategy they've basically learned from their n64/gamecube transition while merging it with another target audience, but I still don't agree with it. Maybe my overall feelings will change some day, and I hope it does. What I do agree with is the fact that Nintendo has never, EVER slacked on delivering a AAA hardcore experience to their customers.
Nintendo in terms of it's games never ignored the hardcore. Whether a game is hardcore or not is determined by the gamer as much as the game; if the game has everything necessary for the gamer to want to strive and reach for to make incredible achievements, then the game is hardcore. If the gamer can make incredible achievements in a game, the gamer is hardcore.
I only have two examples, but I think they're apt.
It's like, if I recall correctly, this one guy talking in Sony's gamer advisory panel about an arch enemy he had in Motorstorm that he would play online, some days he would beat him, but other days this guy would cream him eight ways from Sunday. One day the guy had a conversation during a truce (not a fight, but I would think not 100% at ease, being competitors and all) he asked his enemy how did he get so good and his enemy told him, and I'm paraphrasing:
"I don't have enough fingers to play most games, so I play the games I can".
That guy going for opportunities and doing the best he can made him ambitious at the least. The fact that he plays with remarkable skill in Motorstorm despite his disability and held a rank in a popular game makes him hardcore.
The fact that the guy saw a game that gave him opportunities to advance and to strive for a ranking online and enough challenges to better himself in that game and to make a name for himself makes the game hardcore.
To sum it up: synergy of the player's dedication and the game's ability to allow gamers to strive for something in the game makes each other hardcore.
Now I said all of that to say this: Nintendo knows this and has used this as their central theme in every game they make, although nowadays it's hard to see that.
With all of the available options people have versus gaming in it's infancy makes it a little too easy to dismiss games that have a "childish" look to them as a game for the casual gamer (like Mario games). That's a little shortsighted to do, because the origin of video games started in bright, child-appealing colors; and it belies most games ingenious level design and deceptively simple appearance.
If we go to the core of Nintendo's gaming beginnings, we see Donkey Kong. Simple enough game, isn't it? In this game's heyday, it, and games like it, were so revered for it's challenge at the time that whole movements and competitions sprung up surrounding gamers who could make the highest score. In the documentary "King of Kong: A Fist Full of Quarters" you can see the passion and the pull from "games of old" that hearken back to when there were no instruction booklets, no onscreen prompts, no quick time events, and no more tries than three to beat a game or get enough points to earn another man. It's not game over and you start again; it's game over and you pay some more. You don't know old school hardcore unless you've played under those conditions. And you don't know old-school hardcore game appeal if you don't know a game that makes you start over, on top of paying more money to play it. Furthermore, Donkey Kong had to distinguish itself from other arcade games in terms of color, gameplay, music (if any), sound effects and re-playability. In other words, they only had one shot to make an impression. No demos, no game critics, and no second chances.
When you understand this, you will understand Nintendo and their philosophy regarding games. When you understand this, you will understand why Nintendo have always sold games at a profit. When you understand this, you will understand why Nintendo makes every game like it's their last, and why hardcore isn't Nintendo's middle name: hardcore is interchangeable with Nintendo.
Welcome to Nintendo 101.
You see their standards repeating in just about every game they make from the Mario Brothers, to Nintendogs, to Star Fox, to Metroid, to Wii Sports, and more. Their gaming experience is tough to match, if neigh impossible for any gaming company or console to repeat the complex pattern of excellence as long as Nintendo has. What Nintendo has to realize is that consoles aren't just for kids anymore. Sure, they have seniors playing the Wii as well as kids, but they haven't grasped that all because they make a game for adults (in the Western world) that it won't sully their name. What I do see fading is that old, restrictive Nintendo who used to not allow religious symbols, blood, gore, or sexually suggestive graphics in games on their console. If McDonald's can pull it off I think Nintendo can do it as well.
No, Nintendo didn't lose the hardcore; the hardcore gamers have to be reintroduced to what hardcore is.
With games like Demon Souls and Dark Souls being widely accepted, the hardcore gamers are learning.
With a new IP like Zombi U, Nintendo is learning, too.