They all do: Faust, Impromptu, ChuCK, csound, SuperCollider, etc., etc. I suppose that by itself should convince me that there's no other way (there are things like Orca, but I'm thinking of things that look more like conventional programming languages).
I seldom think about numbers when I'm programming a synthesizer -- I just turn this knob more this way or this slider down a bit. Why can't a music programming language be more . . . gestural? Not sure what the right word is. I want the benefits of a textual programming language, but I don't really want to have to start thinking about sound waves in terms of literal numeric frequencies, particular since I really don't do that while doing sound design.
I don't meant to pick on your project in particular; it looks really cool. But since you're writing one of these, perhaps you can answer my question. Why do these languages ask synth programmers to think in terms of precise numbers when programming an "actual" synth isn't really like that at all?