For the same reason that people don't build brick-only challenges, either: They see "Ooh, shiny weapons" and download 50 different weapon packs, then only host (T)DMs, or they get the "best" RP mod and want to put it to use, or it's a freebuild.
Not that any of that is bad, it's simply that people don't think about skill-based noncombat low-event ways to play very often these days.
Just need one exceptional 24/7 dedicated server, though, and you can inspire a whole new way to play.