It's less that Lua is great for beginners than that it's simple to get started with in the environments where it's embedded. It was originally a configuration language, and in a lot of ways it's still more optimized for "open up a text file and plug in some different values for the running program" than it is for implementing actual logic. (That's what I meant by "non-programmers" in the other comment.)

And static typing is hard to make work when your codebase is made up of a lot of independent snippets of code which run in an environment completely determined by an outside program. You'd need something akin to TypeScript's external type definition files.