I think that Retro has proven themselves more than capable of making a new "best game of all time" with their own ideas now instead of somebody elses, don't you?

How many sales successes like Resident Evil 4 on Wii were there, though? Come on, dude.

My point regards valuing originality for its own sake and why that is a misleading path to walk.

Again, I don't think that changing established IP will do it. It's much better for them create their own.

Retro's original ideas sucked because they weren't competently organized as a studio yet, not because their ideas were original. Metroid Prime would have been great whether it was an original idea or not. Now that they've got five good games under their belt, they are in a far better position to tackle their own project.

Well thats just speculation now...

Well there was Call of Duty 3 and Resident Evil 4 that released in the Wii's first 6 months and each sold over 2 million. Activision chose not to release Modern Warfare on Wii despite COD3 selling better than the PS3 version and not much below the 360 version. Also, instead of making games in the style of the popular RE4, Capcom chose to give it rail shooters instead. These 2 games early on proved that there was a market for mature shooters yet developers chose not to pursue these sales.

Catering to the western market is not all about blood and guts. If Nintendo focuses on the fun, they can make games or support western studios to produce SW classics like, "Zombies ate my neighbors", one of the 1st games I ever played on SNES.

With two big dogs controlling the western market, I get why Nintendo doesn't want to play "me too". But you can still focus on that western market and make different games which gain their attention. Splatoon is a decent start, but still aimed mainly for < 12y/os. Focus more on the teens and make the sunset overdrives,

Hopefully, with the mobile deal catering towards the younger / simpler game crowd, the NX will become that SNES type machine most ninty fans clamor for.

How would more dynamic action not be an evolution of what Metroid already has? It has plenty of action, but at the moment its quite simple. Not saying turn it into a straight up FPS, just make the action that exists better, make it more exhilerating; have the player use the enviornment, incorporate unique combat scenarios, less reliance on lock on: a result of the gamecubes poor C stick. Also I don't get the darksouls comparison; M is atmoshpheric yes, but its so gameplay heavy and not just with combat but transversal, exploration and Puzzle solving. Its no less gameplay heavy then Zelda. Its atmosphere >>> actual lore.

And the comparison definitely points towards a shifts in taste from public and the industry as whole, COD doesn't operate in a bubble. Even ignoring it are saying that you haven't percieved a change in taste since Metroids Primes conception in the early 2000s? That darker, more mature experiences are now more viable as big sellers, or what about FPS as a whole? and what about sci-fi? If Metroid on gamecube could sell almost 3, a reintroduction in 2017 could definitely do more.

The Last of Us isn't exactly COD of duty but we've seen what huge critial acclaim+ timely topic/genere (zombies) can do for a game. It didn't sell itself on action but on atmosphere, storytelling and critical acclaim. Not saying Metroid could ever reach something like  Halo but it could definitely sell above 4m and greatly expand Nintendo's audience. By the sounds of it you want them to try and make an 8-10m seller? Sony has GT, MS has Halo, Nintendo has Mario. It makes much more sense to fufil the potential of something already in existence before trying to brew a new mainstream success and most likely failing like all/any of Sony/MS/Nintendo's recent efforts. 

Anyway like I said, they should do both Metroid and a new IP but I'll agree to disagree with you on Metroids potential

I don't think that good sales on one game proves that there's an audience, no.

As for Nintendo handhelds, look at the kinds of third party games that are selling on them, and comepare that to the ones that are not. Just how different from them are Nintendo's output? Most of Nintendo's 3rd party support on the 3DS are japanese games with tame production values and indies. The games Nintendo provides for it fits and nurtures that ecosystem. The only game that arguably doesn't fit that sells well is Monster Hunter, and even that's a stretch.