That said, this is bad game design. A manual should never be needed.
Manuals in those days were often essential for background story, gameplay, and anti-piracy.
Your statement applies today; game design back then was different, manuals were not frowned upon and often exciting to read through. They were part of the game.
> A manual should never be needed.
Following that rule puts a hard cap on the game's depth and complexity at the design level.
It's probably why most games today are pretty shallow.
More generally, it's also why most software grew from tools into Fischer-Price toys over the past two decades.
This was at the beginning of game design. Everyone was still learning what good game design was and it kept changing as the technical constraints changed.
This was back in the era when manuals (and companion documents) were needed by many, if not most games.
There was a lord of the rings PC RPG I played around 1990, I believe, where many of the NPC interactions said to refer to page N, paragraph M. They didn't have the space to store all the text in the game.
There's nothing bad about a game that needs a manual. It's not going to be everyone's preference, but that's true of everything. Some people like games that you can learn by playing. Some people like deep games that require external material. There's nothing wrong with either one.
I think it's fair. Even an experienced pilot would probably crash on their first attempt at a carrier landing if they didn't do some book-study first.
> A manual should never be needed.
That's going too far.
Also, we're talking about the 8-bit era: 1) technical limits prevented a lot of in-game exposition that you could do now and 2) before the internet, people had fewer options for reading material. I read every manual for every NES and SNES game I ever had, multiple times. If I was into a game my options were limited to 1) play it, 2) read the manual if I couldn't play it (e.g. if I wasn't at home or not allowed to take over the TV to play).