I think the rub here is not that they want to be able to see the script files, it's that they want the javascript behind GMail and other big apps to be released under a Free Software License.
You may not be aware of the dangers of JavaScript — a problem we've deemed The JavaScript Trap — proprietary software running on your computer, inside your web browser.
Danger! Your very soul is at risk!
This page is even worse: http://www.gnu.org/philosophy/javascript-trap.html
Silently loading and running nonfree programs is one among several issues raised by "web applications". The term "web application" was designed to disregard the fundamental distinction between software delivered to users and software running on the server.
Beware, dear reader. They may be starting with this fundamental distinction... but your children will be next!
the tagline in the link reads like a scary movie trailer: >You may be running nonfree programs on your computer every day without realizing it--through your web browser.
Not to mention that should it be licensed under a free model, those security concerns don't just magically vanish. I agree with you summation their stance can be radical and preachy at times much like the Vegan community.
What the FSF doesn't get is that its actually much easier to change proprietary JavaScript than it is to modify a binary running on your system.