The current code does not provide precise responses except "success" or "error" so, There might not be much use if we put them is server! The whole idea is to make error messages more precise in future depending on latest modifications to the code! 

Sometimes, the response code might be "Successful but only showed after approval"
sometimes the response code might be "successful and comment is public"... probably for new users, we might use category 1, etc. which is done on some backend logic

This is a vague idea. The success response message could probably get classified into quite a lot of types depeneding on future developement!

That's one reason why I put messages in server code. I am sure that we don't have to change lots of file for this.. just a respective line in respective view would do fix it if we want to change the code.

Probably this might not be a good idea. What I thought was, having several div's hidden with different messages, and selecting based on what we need wouldn't be good enough (this might lead to overuse of JS selectors too).

If there was a bug on the server and especially after the required operation is done.. and just before adding response message.. Hmmm! the interesting thing is, it will never send success=True in that case and JS is not going to work as what we needed. So, it wouldn't matter either way.

The above was my general idea! However, since our code sends only simple response messages, I moved them totally onto HTML side.