In my experience, when you learn a new language that’s similar to C (be it TADS, Java, C# and whatnot), you don’t have any real difficulty learning the actual language. The majority of the time is spent learning the APIs (like adv3 or .NET.)
A C-based authoring system would still have an API you’d need to learn. The fact that you’re using a language you already know doesn’t really seem to make it that easier.