So you are one of these guys, that want Nintendo to thrive on mobile phones and tablets. Hmm.

Just out of curiousity, how happy would you be if they chose to support Sony only in return for a more favorable seat at the table? 

IMO Nintendo will never ever accept grovelling like a regular third party. They've also seen what Sega's been reduced to. They'd never follow that path IMO. 

That would also effectively IMO wipe Microsoft out of the industry.

I think that would still sell a good 65-80 million units, which isn't niche. They will benefit from higher software sales too using the Fusion model, because they won't have games like say Mario Kart 8 or Bayonetta 2 stuck on the smallest part of their hardware base, by combining both, they can sell to a wider userbase.

The 3DS and Wii U will still sell 90-100 million pieces of hardware between them this generation. 

The main issue for Nintendo is the emergence of smartphones IMO, not so much Sony/MS. They can deal with Sony/MS, smart devices pose a much more difficult challenge for them. That's where erosion is really hitting them.

They would get run out of the market entirely, yes even in the US. 

People still like Mario, Mario Kart, Zelda, Pokemon, etc. an awful lot. They're just not willing in many cases to buy a $300 seperate console just to play those games, but you combine that with what Sony has already going for it, and PS4/5 would become the only console to own. MS would be left with Halo, which would probably then go the way of Minecraft (put on non-MS platforms). 

Yeah well Sony appeals to same exact audience (better than MS actually) and have COD/FIFA/Madden too. They would just have a ton of Nintendo exclusives too. 

If Nintendo did that they would effectively end the console wars and that would probably grant them a pretty sweet spot at the table. 

Which honestly wouldn't be a bad play for Nintendo, they could still continue to make portable hardware (Sony could provide them with assistance there too). 

Wouldn't be a bad alliance at all. In one swift move, Sony gets rid of MS permanantly basically. 

The issue with the PS/XBox brands is there isn't any strong brand loyalty between either. That means any advantage one has over the other tips the scales pretty far, like the PS4 being more powerful this generation, lots of 360 fans are choosing the PS4. They don't care, as long as they get their COD/FIFA/Madden. It would be the same thing if Sony had a deal with Nintendo ... why not, if you have two restaurants with the exact same menu but one gives you free desert or wine, odds are you're going to chose the one with free desert/wine. 

your problem is exactly that, OP. YOUR problem.

There isn't a big difference between the XBox and Playstation to begin with, that's the issue, it doesn't take much to tip the scales in that situation. That's the point. 

"Nintendo games" is kind of a broad statement too, the average COD/GTA player may not give two sh**ts about something like Captain Toad or Animal Crossing, sure, but a really well done Metroid or Zelda or Smash would be a showpiece title for Sony's platform as much as any Uncharted game. 

And honestly most people have a soft spot for a little Mario/Mario Kart, yes even those jaded 14 year olds who will play "only" Calladooty or whatever, they grew up on Mario, same with the 28-year-old. 

Are they going to buy a seperate Nintendo console to play those games? Nope. But if they could get them on their Playstation where they get their main third party games, I'm pretty sure they'd indulge now and again and it would be a fair sized advantage for Sony. 

Contrary to popular belief too, the largest fanbase that Nintendo has is in America, not Europe or even Japan.