Japan is really a "follow-the-leader" culture. While in the west, you had Nintendo fans, Sega fans, etc dueling it out, in Japan the collective consciousness is only built up from what the media researches on, and all they ever devote their time to is the leader, Nintendo, with their Famicom.
I was in for a similar shock when I bought a "Sunsoft Memorial" DVD made by the producers of Game Center CX, expecting praise to be lavished on Sunsoft's great graphics and audio, hits like Meta Fight (Blaster Master), Batman, Hebereke, and Gimmick!. But instead 85% of the DVD went on and on about Ikki, Route-16, and Atlantis no Nazo... I guess media nostalgia extended only to the central years of the Famicom boom.