You mean, like PCs?

Yup - I'd love to play a Mario game on my Xbox One!

I would love to build a PC and just play everything, its close to that already almost all games even metal gear, final fantasy and stuff are ending up on PC these days, very nice. Nintendo is a company that has the most value in its first party, they are the only company that can make a WII U and still sell tons of games on a small install base because the games are just THAT good.

If the NX is a failure the success of pokémon go and other mobile titles might end up going towards the decision we all know, that their software is stronger then their hardware and they could make more money on other platforms.

I'd love to see all companies go third party and develop for PC. Naughty Dog games, Halo, Metroid and Zelda on my PC? Hell yeah.

Nintendo isn't in the same position as Sony and Microsoft. When you buy a PlayStation and Xbox console, you know you'll get most of the big AAA games and many smaller games and indies. Nintendo consoles don't have the same catalog of games, and they miss most of the big third party games and many high quality indie games while the other two miss few of them.

So if you just have a Nintendo console you lack access to most games. The console is less worthy of money to the general audience because of this reason. Also their consoles have dated hardware, are overpriced and support for their consoles is withdrawn very quickly, even when they are successful like with Wii. Also, it makes more sense for them to go third party because their consoles don't sell well while PlayStation and Xbox consoles do.

What about DX12? It only supports windows and not it's competition.  If anyone thinks the tribalism will stop just because there are no longer multiple consoles then they are gravely mistaken.  

Humans are tribal in nature.  War, war never changes. 

I was referring to fan tribalism not corp tribalism which is always going to exist, but with a system put together by everyone there is no need for tribalism.

We have yet to see a time where there are no longer multiple consoles and not a single victor in sight.

There will still be fan tribalism.  Whether it be between software publishers or pc component makers like AMD vs nividia.  

Regardless with Playstation in as good a health as ever your dream ain't coming true anytime soon. 

Sony and Microsoft can make good consoles unlike Nintendo.
Nintendo only makes good games. So they should release them on good consoles.

Nintendo should NOT just go 3rd party. End of story.