I think this involves a big misunderstanding of the web as a medium. You may produce non-free content using Open Software as a tool. E.g., I may write a book using LibreOffice and sell it (with copyrights). I may also embed this book into HTML code and provide it for free to my readers, even when not granting rights to copy or change the text. But, if I would use JS for the means of embedding the same text, I'm off.
And I haven't even mentioned of all the use cases, where a web project is the final product, aka the text, in its own end ...
If your JavaScript were just a bunch of document.write lines, then it'd run just fine, but if you require my browser to run something more complex, it should be a free software licensed program as it's running on my computer and I installed LibreJS to ensure only freely licensed code runs on my computer.
Similarly, you can use Emacs and GCC to write nonfree software, but if you ask me to run it on my own computer, I can refuse.
So you will block all algorithmically produced content (think of web art)? This is, what I would consider an inconsistency.
Even the greatest original text services, think of "In the Beginning was the Command Line", which is served for free, are still copyrighted texts, and this is ok. If you think of a medial form that is genuine to the web, you probably wouldn't go without any algorithmic aspects, and JS is of all solutions for this still the most open one. (The source code is open and free for any one to inspect, even if it is not open sourced.) But JS, especially on the client-side, is more than just a tool, it's also a mean for expressing creativity, with all the potential of being/producing a text in its own rights.
This boils essentially down to, if you need algorithms, let go of any content.
Edit: I may note that I've done some (even awarded) web art myself, and I'm not making a cent from it. But I would be disgusted to see this copied from the very first minute something goes viral and see it served with ads plastered all over in some crude, barely functional fashion (since the copyist would be only interested in making some quick cents and not in the quality and preserving its aspects as a work. And I'm speaking of real cases here.)
