We're talking about programming apps such as Google docs. It is a hard requirement. Your reply is completely useless from technical perspective. Sorry-not-sorry to be so blunt but I have no sympathy for "yeah you can do it without any JS if you remove all features". Let's just go a little further and throw away our computers - we can send carrier pigeons to each other, right? And what's this paper stuff? Useless! Stone tablets 4ever!
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.
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.