Not exactly the future id prefer. Nintendo design there hardware around there games. If Nintendo had to rely on Sony and MS than id expect a drop in Nintendo quality. There games are great because there hardware inspires amazing games (not always the case, cough Star Fox Zero cough) 

Imagin Mario releasing every year on Xbox and PS, instead of unique game elements all we will get is slightly better visuals. If i want visuals id game on PC. Nintendo has been the king of gameplay since the 80s and id rather it stay that way. 

Why does everyone think that if Nintendo develops for any other platform that their whole development process will change and they will suddenly produce lesser games? What is that based on? Are Nintendo developers so fragile and scared that they can't develop on hardware that does not have a Nintendo logo on it?

Was there a single good game on the Wii U that would've been worse without the Gamepad? Hint: No there wasn't. Every single critically acclaimed Nintendo game would've just been as well received if it was on any other console. The "games build around hardware" bullshit is just so that people keep buying the console without questioning their shitty track records when it comes to current technology. People like you make it very easy for them to keep raking in millions by just producing cheap hardware while everyone else is killing themselves to deliver cutting edge hardware for a low price.

But the obvious thing here is that Nintendo have release to very high critical acclaim even without being on the best console specs available. 

I mean, do you honestly believe other game developers would just close down shop if all consoles released were only just as powerful as Wii U? Hint: they wouldn't. If so then I'd say they are failures as game companies if flash is all they have to offer, and sone amazing 3rd party 3ds games prove my point. Power isn't the end all be all, It's just an excuse to allow companies to release hardware twice a gen and pressure the "power is king" minded to fork over the cash. 

The Wii sold over 10m units in its fifth year, so that's a bar that a 50m-selling GC wouldn't be able to touch, meaning no chance that your hypothetical GC would have longer success than the Wii.

The second flaw in your thinking is that Microsoft would not have bowed out after selling only 10m Xboxes (or however much it would have managed in your hypothetical scenario). Xbox was a defensive business strategy for Microsoft in order to prevent the what-they-believed looming disruption of Windows as an entertainment platform by Sony's PlayStation. The real Xbox lost $4 billion in four years and that didn't stop Microsoft from putting out another console because protecting the profits of Windows justified such an expense. The hypothetical Xbox might have lost even more money than that, but Microsoft's motivation would still have been in place, so the Xbox 360 would have come into existence either way. And it would have launched in 2005 all the same because the original Xbox (real or hypothetical) was a lost cause. Microsoft would still have thrown money at the problem, ran a major image campaign and bought plenty of third party support.

Meanwhile, Nintendo would have believed that they are fine after improving their numbers from the Nintendo 64 to the GC, so they would have put out a straight-forward GC2 and got beaten by both Sony and Microsoft. Nintendo would have launched their console in 2006 and gradually lost third party support for all the same reasons as in the real sixth generation, and their first party software might have been even more experimental as Super Mario Sunshine and The Wind Waker would have sold more copies on a console that sold 50m units.

Ultimately, all your hypothetical scenario achieves is postpone the inevitable: The realisation that Nintendo does not fit into a console market that increasingly becomes more about selling a dumbed down PC, because on one hand Nintendo's roots aren't the ones of a PC company and on the other hand consumers do not expect nor want Nintendo to put out a dumbed down PC. What you refer to as the traditional console market is incorrect, because the traditional console market was about bringing arcade games into people's homes and the original console hit games that were created had arcade-like gameplay at their respective cores; it was not about bringing PC games to consoles which is what Sony and Microsoft are all about nowadays.

No, power is the reason why they can deliver all kinds of experiences and not just cater to a specific kind of fan. Power does not make games worse, it just gives developers more freedom. What they do with their freedom is their choice.

Believe it or not but even Nintendo developers would welcome it if they had more freedom to develop their games instead of being so restricted on extremely closed platforms.

They do not produce great games because of how restricted the platform is but in spite. Now imagine what they could produce if they're freed from the shackles.

But it's very possible to do. Saying Nintendo should go third party because they don't have the most powerful console is to say they can't provide amazing experiences without it, which is false. I have enough faith in the talent of game developers to believe they are capable of making new great experiences on any platform, even (as I mentioned before) the 3ds. It's their job to be able to do that. 

Sony's piggy banks dwarfed Nintendo at that point, despite Nintendo's success. Sony was on top of the world in multiple markets in the 90's.

Basically, Nintendo didn't read the fine print that Sony slipped in (this whole episode reads as one experienced company taking advantage of an amateur) and likely couldn't have had much success in court given the language of the agreement clearly favored Sony. Nintendo had little choice but to back out at that point, and Sony had learned all they needed to about making a video game console from the experience.

agreed with some other comments, the Wii, Nintendo's biggest success, came after the Gamecube... it obviously didn't deter the company

also fun fact: Nintendo actually made MORE profit during the GBA / Gamecube era than Sony did in the same period from the Playstation 2 (the best selling home console of all time). The point I'm making is the Gamecube wasn't poor in terms of profit

hardware sales aren't everything. I personally think the system and its controller are fantastic. The mini disks may have hurt them with third party developers BUT it did stop game copying and, again, Nintendo had healthy profit in the period