While you can still inspect the DOM and so on, but it's not as accessible if the source isn't there. So in fact, open source code on GitHub and so on is the best hope for learning and reusing, but that puts JavaScript in the same basket as every other language.
1. http://ajaxian.com/archives/the-end-of-days-for-view-source
It's really not a problem. It's also quite amusing when I see "protections" in place, like my local Yellow Pages that encrypts phone numbers that get decrypted when shown by a local Javascript routine, done of course to prevent crawling.
Obfuscated code is not readable. However a smarter view-source can take care of that - imagine a view-source that worked like an IDE. It could beautify the source-code (I'm sure you can already find plugins for this) and once you figure out what a variable / method does, you can then automatically refactor the code, renaming that variable/method.
It takes a bit of engineering, but obfuscated Javascript is still high-level enough to be useful.