*Tin foil hat time*
I honestly think he's onto something somewhat here. I don't fully agree with the Splatoon thing because it's a great game, but I could imagine something like ARMS releasing on PSN and it getting massively ignored -- even if it got very strong review scores.
I also think this works two ways: games like Puppeteer, LittleBigPlanet, and Tearaway would be much more appreciated if they had Nintendo on the box IMO. I was playing the Robot Rescue demo in The Playroom VR recently, and I couldn't help but think if it was the EXACT same experience with the character model swapped to Mario, people would be going absolutely mental over it.
I dunno, I didn't hear Colin's argument so I don't know how forcefully he put it across, but there is a nugget of truth to that line of thinking IMO -- no matter how small.
EDIT: To be clear, I don't think any of this has to do with critics actively trying to help Nintendo sell games. That part's certainly nonsense.