Why not a checkbox to turn off HTML? It would be just as "useful"...
I do need JS to achieve all my goals that can be achieved with JS. For those things that can be achieved without JS but often mistakenly involve it (hamburger menus, animations etc), I use plain markup and CSS3. But I'm not going to ruin the UX on mobiles, where in developing countries traffic still matters, just for some paranoid freaks' sake.