overgeeked
Open-World Sandbox
Because it’s the earliest and easiest version of the Basic game with by far the most sales. It’s the most widespread of the rules light versions of D&D. More people started with it than the other Basic editions. So, nostalgia. When the OSR came around B/X was out of print and not available as a PDF, so OSE. There’s also momentum. Like 5E, everyone’s playing it so everyone plays it.Full disclosure: I legitimately do not understand why OSE is a thing. It's just B/X. Why is THAT the one that a significant portion of the OSR locked on to?