You are correct. I meant that Mojang was saying they would consider open sourcing Minecraft itself when it's ready and has raised sufficient funding (have we reached this point yet?). My point was that modders are providing significant value for free to private companies (and are happy to do that as lon as they're credited) and i wish such energy was directed towards a FOSS game ecosystem instead of continuing to enrich the same crooks who derive money off dark patterns (subscriptions, lootboxes) and exploited workers (gamedev industry is famously harsh).

Also, each software has its guidelines to build mods. I feel like if a game had modding guidelines suggesting to open source, modders would be more than happy to do so; if not, open-sourcing a single-person project can be considered more work (eg. setup git).