Well yeah, they aren't amazing revelations that will change gaming forever. But some of them are good things to keep in mind.
Like, if you make a game that can't be understood on at least a fundamental level within 10 minutes, you'll probably lose a lot of players. It's a good idea to pace your game so that the player encounters something interesting (maybe a powerful enemy or a unique item or a story event) at frequent enough intervals that they stay engaged.
Those sorts of things. They aren't hard to understand, but developers, even professional ones, screw it up all the time.