BVM compiles to bytecode.
So can Lua if you prefer... look through the document.
Where I mean "script" can be either text or bytecode...
BVM is also a user made thing(of course, not BRL), users who choose Lua may have previous knowledge to it, or have some point to utilize it.
However they are used in different fileds, those who choosed Lua, mostly targeted to user-driven mods.
I don't think user made mods is a no-no, but I hope they're opensourced, or source available for purchase.