K, let's look at this saturated market. These are the 2D platformers released by Nintendo from 2010 to 2013 (when DKCTF was announced):
- Kirby's Epic Yarn (2010)
- Donkey Kong Country Returns (2010)
- Kirby's Return To Dreamland (2011)
- New Super Mario Bros. 2 (2012)
- New Super Mario Bros. U (2012)
- Donkey Kong Country Returns 3D (2013)
6 games (2 of them being DKCR) from 3 franchises hardly feels like a saturated market, although I won't deny releasing 2 new NSMB games so close to each other was a very silly move, as was releasing DKCR3D so close to the announcement of DKCTF. I didn't include 3rd parties in here as the original argument was about Nintendo having way too many 2D platformers, which is clearly inaccurate. Even then, including 3rd parties wouldn't increase the number much as not many 3rd parties actually release platformers.
I'm, also, clearly ignoring indies here since the argument changes a lot including them. If the 2D platformer market being saturated by indies explains the backlash towards DKCTF by the Nintendo fanbase then people wouldn't have been hyped by Metroid Dread as 2D Metroidvania is a ridiculously saturated market thanks to indies as well. Similarly, people wouldn't get excited about the possibility of traditional Paper Mario returning if indies were to blame, as there's no shortages of RPGs in the market either.