I took a photo of this too. Highest ratings per game type.
So the ratings don't make that much sense as you see.
Also, I noticed that they only include games from 1987-1992, or maybe it was up to 1993. Anyways, no Zelda or Super Mario Bros.
Here you can see the highest rated puzzle game was Lemmings for the Super Famicom. The highest rated action game was Castle of Illusion (Mickey Mouse something or other) for the Mega Drive and for shooter games it was Fantasy Zone for the Famicom. Maybe they rate games based on first impression. Those games aren't considered top games in Japan today...