Even still, you would have to develop multiple games normally, but not release them until a bunch were done (which would be ridiculous and pointless)...

Rare also had a giant head start on the N64.  During the development of Donkey Kong Country they allotted large sums of money to buy expensive Silicon Graphics workstations (SGI Indigo 2, Challenge L/XL) because they developed a new rendering technique they called ACM (Advanced Computer Modeling) that required intensive processing power.  They were also one of the first studio's in the UK and Europe to invest so heavily in the expensive SGI workstations.

Rareware's prowess and skill with with the SGI machines impressed Nintendo greatly and was probably one of the reasons Nintendo chose Silicon Graphics (SGI) to develop the graphics processor for the Ultra 64.  I think development of Goldeneye started on Silicon Graphics Onyx machines before the N64 was finalized.

What I said was that Nintendo didn't support Conker.  They refused to publish it.  Rare ended up publishing it themselves in NA and THQ did in Europe.

Nintendo has only so many resources to create and release games.  They have to make choices.  They can't just greenlight every idea.  They have limited manpower, limited time, and limited money.  Some games that appeared the previous gen don't get a sequel.  Others do.  Some brand new games get made.  And some games make an appearance from 2 generations or more ago.  An example of that being Sin and Punishment.

I wanted to check to see the number of games Nintendo has published for their most recent consoles.  This is for all regions.

This chart certainly surprised me.  With as prolific as Rare was during the N64 years, I expected the overall total to be much higher than the Gamecube and Wii years.  Not true.  Perceptions don't always equal reality.  The Wii does have 5 "New Play Control" games in there, so you could knock those out of the list.  Yes, some games are region specific, but this gives a rough idea of Nintendo's output.

I do wish NOA would have localized some more games, like the ones you mention.  However, that is an NOA problem in specific, not Nintendo in general.  Those games were all published in Japan, Europe, and Australia, so I don't know what the hell NOA's problem was.  If you want to argue that Nintendo should not be wasting time with games that will not release in all regions, I will 100% agree with that.  Or if you want to argue that NOA should be bringing in games that were localized into English anyway, I will 100% agree with that too.

I don't know what to tell you about Retro.  I can only assume they are working at full capacity.  There would be no reason for people to be sitting around doing nothing.  This is everything we know they have been involved in so far:

2002 - Metroid Prime
2004 - Metroid Prime 2
2006 - Metroid Prime Hunters
2007 - Metroid Prime 3
2009 - Metroid Prime Trilogy
2010 - DKCR
2011 - MK7
2013 - DKCR 3D
2014 - DKC Tropical Freeze

So they were working on smaller projects as DKC TF was being developed.  Unfortunately, no one is going to get excited about them co-developing a game we knew was coming anyway and a port.  I understand they did the DK assets in MK7 and the retro tracks.  Not exactly sexy work, but someone had to do it and Nintendo gave them the job.

I heard that, but honestly it was one of the crappiest survival and horror games I have ever played. It had terrible balance issues, and some really annoying gimmicks, that didn't really work.

Rare's games were pretty enough, at least on a technical level, but I wasn't impressed with the way most of them played. I wasn't surprised when Nintendo parted ways with them. They were already starting to go downhill, although Perfect Dark was pretty good.

That explains the abnormally high quantity, but still doesn't explain the abnormally high quality.

Doing games and CGI in general doesn't really work that way. That's why movies take over a year in post to finish the stuff. Back in Star Wars days. They took 4 months. The more detail in the game, the more longer it takes a human to work on it. Compare Mario's model in M64 to Lara Croft in TR2013. You could knock out Mario's model in couple of a days. Lara would take weeks just getting her hair and clothes to not colide all the time. It's the amount of detail into the object that takes the time. Not really the hardwares power.

That's all up to Nintendo if they want to hire more teams to work at the same time. That's the only way the system wouldn't have droughts. If they want to ignore 3rd parties. But they so far can't or won't for whatever reason.