I'm sticking by my theory that to properly tell the story of just the 8-bit years and earlier, from Spacewar! to Odyssey to Atari to NES with all of that era's consoles in between, would take anywhere from 8 to 13 hour-long episodes, leaning strongly toward 13.
As long as everyone keeps sticking to 90 minute one-off specials, there'll never be room for the whole story.