I wonder if creative people can be bothered to learn Rust, or perhaps an easier path to adoption could be a simple DSL.

They can! I watched an interview with the makers of this framework and they're artists themselves that learned programming to make art.

Rust can run fast and thus is attractive for this kind of thing.

The quick run speed is great for shortening the feedback loop. I've had great experiences with Lisp-style environments for that reason, and the language is much higher level than Rust while still offering good performance. I've mainly used Quil, the Clojure wrapper around processing: https://github.com/quil/quil