Looks like people haven't learned anything from the SEGA situation, and most probably weren't even there when SEGA was relevant to understand the quantity and quality of SEGA games to compare with today.
Would a third party Nintendo be financially successful? Probably yes.
Would it mean killing the majority of smaller internal studios, shrinking the remaining teams and total extinction of experimental titles that may or may not have worked and been successful? that's a yes too.
I love Zelda and Mario, but Nintendo is more than those titles to me.
People should understand that what Nintendo is doing is figuring out new gameplay ideas and then adding a familiar skin to market it. They are constantly pushing their gameplay experimentation, to create new ways to interact with the games, and they have set this as a priority over other aspects of electronic entertainment. People who play Nintendo don't do so because they want the new XX series entry, but because they want to see what gameplay implementations the next generation of XX series entry would bring. Sometimes it works, sometimes it doesn't, but they do experiment, where most other publishers follow a successful recipe and make more visually pleasing entries with it.
Some say that the lack of certain entries for a gen is a sign that Nintendo is already abandoning IPs, but they should consider two things.
1) Nintendo has a big library of IPs, and whether you want it or not, we saw most of them in last gen. A couple of IPs are allowed to be absent.
2) When you ask why there is no Metroid game, you should understand that probably Nintendo hasn't figured out how the Metroid of the next generation should play. Metroid is an exploration adventure, not a FPS game, and Nintendo will always struggle to make a good exploration adventure entry out of the IP. Prime will not always work and honestly this circle has closed anyway. Nintendo tried other approaches with the IP (see Other M), and really it didn't work. It happens.
So don't really write Metroid off just yet. When Nintendo sees they have a good idea at their disposal that fits the IP, they will make the game.
SEGA did the same for a long while, and while some may be happy with newer entries (I'm not) or with how much better the next Yakuza game is compared to the previous (probably the only game they are still capable of developing in house), old SEGA fans miss all the weird games which sometimes succeeded, sometimes didn't, but are considered classics today.
Also it's been a while since we had one of those threads. Nintendo hasn't even properly announced their next HW, let alone release it, and we already have third party talk. FFS, pick another publisher for your concern trolling for one year, just for variety.
Also:
That gif is really useful today :
Beautiful XD