More competitive games can’t afford any type of easy reverse engineering due to the cheating factor.
Click on any mod, and you can see the decompiled source. The mods use function hooking to run before or after certain functions are called rather than the event based system you see in Minecraft plugins.
The nearly-infinite expandability and modularity of Minecraft is partially due to the simplicity of the art, core game mechanics, and lack of storyline. Good mods are harder to make when the world they must integrate into is more complex.
I think this means a lot of games wouldn't see the kind of sustained success Minecraft has seen, even with more "open" development practices.
I hypothesize that the "open world" craze of years past was an attempt to capture Minecraft magic, but those games lacked the thematic open-endedness that really facilitates Minecraft's longevity.