There are certainly refinements that can be added with JS, but JS is not a requirement, and certainly is not for rendering an editable page.
And as a user, it is a hard requirement for me too. I never want to go back to locking and versions, that's absolutely terrible and completely kills the workflow I have with my colleagues. Collaborative docs editing is single most awesome development of the modern web and users are choosing the otherwise not-so-good Google Docs solely based on this feature. Perhaps not every user needs it - but there are countless users that do. If I wanted to edit without collaboration I'd use Word - much better UX and document editing capabilities... Sadly no truly working collaboration - it's too much like locking/versions, so it's not an option. I'd rather use collaborative raw text editor than the best of the best locking/versioned WYSIWYGs.