I'm in a related field (I do a lot of signal processing in Pure Data), and I also keep an eye on the live coding scene. You're absolutely right here in that Tidal isn't about signal processing, it's about a flexible, creative, and expressive way to issue musical commands as text. It isn't so much an audio programming language, as it is a musical programming language.

Other languages such as Chuck, Supercollider, Pd, or Max are much better suited to the signal processing side of things (though there are certainly plenty of pained souls who have done plenty of musical work in these languages).

Edit: I can safely say that if you're planning on getting into live coding, Tidal is the way to go. I wouldn't recommend anything else. There be dragons.