More I am just confused for why the game was chosen. SM64, Zelda OoT for example I could easily understand the community motivations behind decompiling. This not so much, which makes the whole endeavor even cooler.
The other factor to consider is OoT and SM64 are Nintendo properties. Nintendo is one of the most litigious companies in the industry. That alone may shift people away from some of those big name titles owned by them.
I'm not sure "community" was always the reason, but we might be talking about different eras. Back in the late 90s and early 00s there were the pioneering scenes for modding, emulation, fan subs, remakes, etc. and it was all highly competitive.
I don't mean to shit on anyone's legacy, but it seemed more ego driven and like there was something to prove either personally or politically. It was cultural and maybe even spiritual. Anyone working on this stuff felt powerful. Nearly a century of broadcast media and being told what to do and how feel by people from far away was ending. Disassembly felt more like deconstruction. It didn't feel like love. It was hacking. There's a reason why one can still shout "hack the planet!" into a crowd of nerds and get them to instantly light up.
I'm not even saying all this as an old fart. Things just changed so fast since then. I'm in my 30s.