For me it's about being more intentional with what I post instead of just letting stream of consciousness out. It's a good rule...but it is hard for me
I don't mind additions (for further clarification instead of clogging with another post) but typical form on the Internet is to write EDIT: and add anything you forgot.
It would be cool to add a forced
EDIT: (insert new text) only for additions kind of like a quote but the system is reasonable and requires more thought so I like it.