It's fine when the functionality actually requires JavaScript. The trouble being discussed is when displaying plaintext requires JavaScript for no particularly good reason.
It's 2013. I don't think it's especially unreasonable to assume JavaScript is universally available when developing a feature. As hnriot said, if you choose to browse the web with JavaScript disabled, you accept the fact that large swaths of the 2013 web will not work.
Essentially all of the browser exploits over the last decade have had javascript as a necessary component. Irresponsible use of javascript forces your users to expose themselves to attacks for your convenience. That is abusive and is the kind of thing that will drive away your most sophisticated users who are likely to be be adoption trend-setters for any endeavor not primarily pop-culture oriented.
Google's inertia means they don't have to care, but nearly everybody else has a lot more to lose from alienating those users.
