Javascript already does that. If you look at any website nowaday you will find minified JS that is impossible to understand. What's the difference with a binary format at this point ? It does not change the fact that those blob are executed in a sandboxed environnement with a permission system. At least WebAssembly is more efficient and will make it finally possible to use staticly typed langage for web developpment.

A minor point: To be fair, minified JS is not exactly a hard barrier. Conventional minification is just removing extraneous whitespace, newlines, comments, etc.. Except for the lost comments (which are definitely a pity if it's well-commented code), it's easily restored with an unminifier.

Is WASM really a proprietary code blob? Or the WebAssemsblers will be proprietary code blobs? Isn't it being done by guys at Mozilla, Google and folks. Or are you confusing Assembly lang that is used with different CPUs and this. If so try this:

[1] https://auth0.com/blog/7-things-you-should-know-about-web-as...

[2] https://gotechster.com/2017/04/web-assembly/

We had that before with native plugins and extensions. We can also install random programs on any OS. It's really not a big deal.