Zeroth posts are fine as well, but they're often used for something other than the front post of the role play. I've also never met anyone who likes the zeroth posts, they're ugly and imposing. 

EDIT: The front post is where the bulk of the important information goes, co-GMs not being able to make edits is a little silly. Nobody is saying it needs to be implemented immediately but I definitely can't see a problem with it. Especially if it's a feature that can be toggled when creating a thread.