I don't know of anyone who actually audits the JS they run. I know people (like Richard Stallman) who don't run JS at all, and people (like my roommate) who use NoScript with exceptions for websites they trust—which is a trust by website, not by code; they'll trust any JS that origin produces in the future. I suppose there are people running GNU LibreJS and running any JS that claims to be freely licensed, but again without looking at the code to see if it's heavily obfuscated. And then there's the rest of us, the vast majority, who just run all the JS we se.

If we already had people who audit JS before running it, preserving auditability would be worth doing, but keeping the ability to do something that (I think) literally nobody has done in over 20 years of JavaScript isn't worth trading off actual technical improvements for.

Fortunately we have something very different and (IMO) more practical, that makes this very different from an "index.exe" model: we have isolation between websites enforced at the browser level. aim.exe can read my saved quicken.exe documents. hangouts.google.com cannot interact with my bankofamerica.com account; it can't even know that I have one.

I think I have a right to see source to all the code that runs on my device with full privilege. I also think I have a right to limit the powers of code to which I don't have source, including both limiting what sorts of things it has access to and how much CPU, memory, etc. it's allowed to consume. I don't really know that insisting on the right to see source to code that runs confined is actually going to measurably improve my computing freedom.