It doesn't, if the Kevin Callahan rumor is legit:

"Diddy Kong Racing 2 is a collaboration between Monster Games and Retro Studios with Kensuke Tanabe as the producer. Monster Games is also working on another side (small) project that isn’t related to Diddy Kong Racing 2.  Retro Studios is working on a separate main project of their own as well."

OT:  If the rumor link is true, this game has been a long time coming, guys.  It doesn't mean that Retro couldn't be working on something as ambitious as Prime 4 for a while now, as they're likely just making contributions to DKR as opposed to being the main team on it.  Just having received Mario Kart I can understand some people not being excited over this, but if it is indeed true let's at least see how the game is coming along before condemning its existence.  If it's anything like DKR on N64 was, it could be truly great.

It would make sense for Monster Games to make DKR, they have some experience with arcade racers already and this could be their occasion to make the big step.
As for Retro obviously they should focus on something more ambitious, but they could still work on the project as technical supporters, like they did on Mario Kart 7.

Well, there was a rumor a while back that Retro expanded by a sizeable amount. Maybe it was to have a smaller team to work on projects simultaneously?

Though quite honestly Diddy Kong Racing 2 is...a little disappointing even if it is a side project. How about a new Mario RPG or sending a reconnaissance team to find out whatever happened to FE x Shin?

They were making the argument based on passed sales and trends. No one can predict the future but we can speculate based on what happened in the past given the sales trends. Also you seem to think there is no overlap of fanbase for DK and Metroid and those who enjoyed the former simply don't care about the later. 

I'll give you an example of speculation based on past trend. For example, it can be speculated that Zelda U will be delayed from 2015 to 2016 as both previous enteries, Twilight and Skyward, had major delays. Doesn't mean it would happen for sure but there is a chance that it probably will. 

Another note: Most franchises will have one of their lowest sales iterations on Wii U. Be it whatever you want. 

Thank you, I am!

If true, this is a colossal waste of Retro's time and talent.

Did the sales of Tropical Freeze not get it through Nintendo's heads? Gamers want something more ambitious from the studio, like the Metroid Prime games were back in the day.

Retro hasn't been good in over a decade.

Now that I would contest. Prime 3, DKCR, and Tropical Freeze may not have reached the same level of brilliance as Metroid Prime 1 (though to be fair, only a handful of games do) but they were still great games with exceptional craftmanship, polish, and entertainment value.

Don't waste a good studio on 3D Donkey Kong. Artoon or whatever they're called after the latest bankruptcy just finished Yoshi's New Island, foist them on that.

Why don't you believe a wordpress blog that was set up a whole day ago? >=(

Im probably the only one that would be excited for another Donkey Kong Country game.lol