Just doesn't have the giant userbase, and since core adoc has basically "enough" functionality, it never got the hacker culture in its guts since you don't need to muck around in its guts for transclusion, variables, or conditionals. In short, Asciidoc is constantly fighting the headwinds of not coming from the JS ecosystem.

That damn Ruby heritage . .

Which is kinda funny, because Ruby is one of those languages that cranky hackers almost ubiquitously shrug and go, "yeah, it's mostly right". Whereas JS . . well, maybe if Ruby got built every damn which way we'd be making fun of it too.