This is pure nonsense. WebAssembly is no more obscure than asm.js or minified JavaScript. "Binary" versus Unicode-enabled minified and transformed "source" is the same thing.
You can get text out of WebAssembly as well as you can get text out of minified JS.
Further, users don't care about this. It's literally just developers. Open Source / Free Software is a super valid discussion to have, but I highly doubt any non-technical user cares.
I guess you may be right! I presumed WebAssembly to be some sort of opaque "goto-soup" (unlike minification), as the term "assembly" suggests.
But I looked it up and it seems WebAssembly preserves the structure of the original document, just like minification, at least that's what I understand from the following quote:
"In practice, outer blocks can be used to place labels for any given branching pattern, except that the nesting restriction makes it impossible to branch into the middle of a loop from outside the loop. This limitation ensures by construction that all control flow graphs are well-structured as in high-level languages like Java, JavaScript and Go."
See: https://github.com/WebAssembly/design/blob/master/TextFormat...
Also, it probably means the end of the Web as we know it.
Browsers very likely should treat closed source like they treat our microphone or camera: don't give access unless the user consents.
But do allow it to run without consent if, and only if, the source code is public.