I agree that JS code will generally be shorter than Java code because 1) you don't explicitly describe your types, and 2) JS is more expressive and there are things that you can just do more neatly.
However, there are many classes of code and #2 applies more to some than others. If you are writing something algorithmic like Peter Norvig's famous spell checker[1], the primitives of your language make a big difference. On the other hand, if you are writing something that is larger but of lower complexity where your code is more like configuration of a bunch of pages, this makes less of a difference.
Also, it's at least possible that the people who see your code assume a higher standard of maturity than your 6kloc has. We've all tried creating an apparently complete app rapidly, only to work on it for ages afterwards, implementing fault tolerance, graceful degradation etc. etc.
anyone has evidence of similar projects done in java and javascript showing how js is much more expressive?
Sure, the lines end up less wide, but while you gain something by using function() over inner classes, you also end up reinventing package declarations and visibility all the time, so I don't see a clear advantage of one over the other.
(notice: I do understand people will generally do things in Java that they won't in JS, such as adding setters and getters, but I have seen that done in plenty of "big" js libraries, so I doubt that counts.)
However, there are many classes of code and #2 applies more to some than others. If you are writing something algorithmic like Peter Norvig's famous spell checker[1], the primitives of your language make a big difference. On the other hand, if you are writing something that is larger but of lower complexity where your code is more like configuration of a bunch of pages, this makes less of a difference.
Also, it's at least possible that the people who see your code assume a higher standard of maturity than your 6kloc has. We've all tried creating an apparently complete app rapidly, only to work on it for ages afterwards, implementing fault tolerance, graceful degradation etc. etc.
[1] http://norvig.com/spell-correct.html