Reading this article makes me feel like the team that built this wasn't just building a game. It feels like a passion project where the detail was important, not because it made for a better game, but because it mattered to the people building it.
FS was Bill Gates' hobby project. The game team was disbanded (licensed to Lockheed as Prepar3D) one year after he stepped down.
Around FS2000 an oceanographer was hired to model the ocean waves.
So very focused, deliberate effort has always gone into FS, but that's more to achieve realism than for fun.
My theory is that military sim applications drive the realism, and probably there is military funding, so it's not really a "passionate gamers" angle. This would explain the quick licensing to Lockheed (for govt. contracting requirements), which is unprecedented for a game if you think about it.
(Atari Battlezone was likely also studied and used by the US military. I have some high scores on that. There's one in the SF pier historical arcade, as well as most of the Atari classic machines.)
