You might not want to bundle Rust in with C and C++ in this context. Rust is pretty accessible to developers coming from scripting languages (JavaScript, Python, etc).

Direct DOM manipulation (and the ability to send reference types across the JS-wasm boundary) is a pretty big deal though I think. Currently it doesn't make an awful lot of sense to build code that interacts with the DOM in WASM (although in Rust there are automatically generated bindings that go through a JavaScript shim).