You'd have to also change all clients to not execute JavaScript in text/html, if you want application/html to have any bite. Another option, perhaps more likely

You'd have to also change all clients to not execute JavaScript in text/html, if you want application/html to have any bite. Another option, perhaps more likely to have an effect, is to have clients with no JavaScript enabled to include a parameter with the accept type, e.g. `text/html;profile=no-js` or some such. Servers that don't recognize the parameter can just ignore it, and servers that do recognize it can serve up a no-js response. Any client that doesn't know this parameter will just functions as normal. No need to invent a new content type.