If Firefox's developers are worried about people not understanding why a page doesn't work, another potential solution would be to provide users with some feedback. For instance, if Javascript is disabled but present in a page, perhaps show a (simplified?) small debugger box showing the next lines of Javascript which would have been executed and some sort of an obvious Run / Play button to start the script.

I'd prefer if browsers treated the Web as less of a black box, and if they erred more toward helping users understand the world they are exploring.