It's not by design, at least mine, but rather a legacy of WordPress's blog roots.

It organizes people into three main privilege groups: Authors, Editors, and Admins. That's too coarse-grained, and it's the mismatch between our egalitarian expectations and a categorization from the blog world that's chafing.

Authors have fewer privileges than a discussion participant should have, including self-editing rights. And Editors have more privileges than participants need, but fewer than moderators need. But Admin confers too many dangerous technical powers to give to all but a select few. So at the moment, nobody has exactly the right mix.

Damn if it doesn't sound like Goldilocks and the Three Bears, doesn't it?

Anyway, I'm aware of the problem, and how it can rub against our social expectations. I'll have to fix it.