I'm thinking of small devices like wireless routers, phones and maybe even wristwatches. I like the idea of having a full stack framework for web apps, served locally on a tiny device. You could reuse a lot of code that way and at least for phones, potentially avoid some of the cost of having a native app with totally different code from your web app.

But yeah, LuaJIT recently added support PPC and soon will add ARM, so point well taken - to do what I'm thinking of, it may not really be necessary to have anything in C.