for one thing, the set of programming languages that are easily embeddable is very small and lua has an enormous lion's share of that niche
if i were to create one myself *even fewer people* would use it
and i don't know how many people would want to do game dev in https://github.com/gluon-lang/gluon
a third alternative is making a game engine around an esolang, like befunge or something
i find the prospect hilarious but i doubt anyone else would take to it the same way
yet another alternative is a fantasy console! but i'm already doing that