WASM by itself doesn't provide new APIs, it's still just a different way to expose the Web platform. So WASM being optional doesn't limit anybody in what they can do. Having WebGPU optional does limit what you can do on the web. We want WebGPU to be available in a wide sense (accessibility, dependencies, portability, everthing).
It seems you speak with "we", as if you were part of the committee? If that is a yes: how can we become part of that committee to amend this mistake? Who has voting rights?
WebGPU community group is open to anyone interested: https://www.w3.org/community/gpu/
Anything you can do with WebGPU you could do in JavaScript, in the same sense that anything you can do with WASM you can do in JavaScript. The only difference is performance.
There's not really a good way of writing WASM without dependencies inside a browser.