People like you are exactly like the PC folk who said Apple had to go OEM and put their software on third parties.
Nintendo isn't in danger yet and there's no reason to give up their biggest advantage- not relying on any other company and owning their stack.
What they actually need to start doing is admitting that Apple ate their "blue ocean" casual gamer lunch and start appealing to their original fan base. Nintendo lost a lot of their core with the Wii because they started simplifying core franchises for the sake of new players- Metroid Prime 3 and Other M and Zelda: Skyward Sword were all simpler and more linear, and Super Smash Bros Brawl was much slower and had a capped skill ceiling, more random events, too much defensive buffs, no more combo system, and more rubber banding compared to Melee (which has the best game design from a fighting game perspective in the series).
Nintendo is showing signs of recognizing this in recent interviews, but the new Smash Bros is still pretty much Brawl. We'll see how long it takes them to figure this out.
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This was more of an accident in licensing. Nintendo tried to renege and cancelled the Philips SNES CD adding and couldn't revoke the IP rights they gave.
Historically, he's right. Nintendo makes less third party software than Apple does (iTunes).