Why?
JavaScript the most misunderstood language
We were in the dark ages and still are for the general development community to accept that JavaScript is a powerful and versatile language. It's simply not mainstream.
The only recent advance is that node.js has become buzz-wordy and people are starting to accept that javascript has other uses..
I've been keeping an eye on the JS & HTML5 development for windows 8 and the reaction from the .NET community was "dear god why?".
It's simply fact that most non-web developers still see JavaScript as that toy language you use to make those scroll over menus in your browsers.
Admittedly JavaScript doesn't align with "modern development practices". For me JavaScript is still a hacking language I crack out with vim & the internet is my documentation. There is no IDE, there are no development tools, there is no auto-complete or "intellisense", there are no click and drag GUIs.
In the world of Java and .NET developers they are wedded to their GUIs & IDEs and would not be able to program in vim.