Why any TRUE gamer would want Nintendo third party is completely beyond me..
I hope this helps you: http://www.geekcomix.com/vgh/fourth/nesbad.shtml
Sony and MS (and their third party lapdogs) running things by themselves would kill gaming.
Sony has dominated the 5th and 6th generations and I believe gaming is still alive. Don't you?
Just look at how MS completely sold out gamers with all the DRM shit initially with the Xbone
Have they?...while Microsoft tries to, Nintendo really does it. Because of the region lock, Nintendo can better squeeze each market of the world. And because of that very same policy, some gamers have wasted money on 2 3DS consoles. Now you tell me what is worst.
Look at how Sony thought everyone would run out and spend $599USD on a freakin Playstation 3..
Still, at 600$, PS3 was the cheapest solution of the market. You can't say that a 60k€ Ferrari is more expensive than a 25k€ Ford. It is actually much cheaper and everybody would understand that although I don't think if that happened Ferrari could ever sell more than Ford. Same thing with a 600€ PS3 and a 250€ Wii.
Sony made some bad decisions with the PS3 and they took responsibility for it. They created an unecessary hugely expensive PS3 and they accepted losing hundreds of dollars per console. Nintendo made many (not some) bad (rather greedy) decisions during decades and they didn't took responsibility for it. Not only they did it at the gamer's expense but also they haven't taken lessons learned from it.
Nintendo going 3rd party won't kill gaming at all. I actually think it would strive like never before. Gaming will only be dead when people with your thoughts dominate the market.
Prediction made in 14/01/2014 for 31/12/2020: PS4: 100M XOne: 70M WiiU: 25M
Prediction made in 01/04/2016 for 31/12/2020: PS4: 100M XOne: 50M WiiU: 18M
Prediction made in 15/04/2017 for 31/12/2020: PS4: 90M XOne: 40M WiiU: 15M Switch: 20M
Prediction made in 24/03/2018 for 31/12/2020: PS4: 110M XOne: 50M WiiU: 14M Switch: 65M