I understand that thinking but it's ignores reality. To do what you want you want means maintaining 2 codebases (even if just for sub-parts of a site). It's really easy to say "This specific page could be static" and you are right, it could, but it would mean having fallbacks for every JS interaction on the page (or removing them if the user has JS disabled). There simply aren't enough people who die on the no-JS hill to care about, especially since it means ongoing development maintenance, testing, design/UI work, and the list goes on.