Marshmallow-Go makes few attempts to guide you in your studies and has little to no interest in the inner workings of the Japanese language. It makes no claim to be an expert of any kind. This is about your day-to-day, what you do with the language once you put the text-books on the shelf, leave your classroom and venture into the real Japanese speaking world.
It's not about what learning a language can do for you.
It's about what it might do to you.