The site relies quite a lot on knowledgeable people to review and edit things, and the more grunt work that entails, the more you have to really care about being a part of the site to commit to it. The types who are interested in shouldering that burden will tend to be the ones who are extra hardcore, who are also more likely going to be impatient with mistakes and newbies.
"Natty started to flag answers automatically once it had detected a particular answer as a non-answer with considerable accuracy."
It might be that I don't understand - does Natty flag something directly, or flag them for the moderator?
On the other hand, the Heat Detector bot sounded it was punitive too, but in a way that might strengthen the community. (interesting thought - could it flag moderators?)
Why shouldn't it? Moderators are just like normal users but with some extra privilege regarding editing/deletion.
There seems to be a bit of confusion on how SO moderation works every time SO is discussed here. Most of the moderation is done by other users. I'm very active in editing/flagging/closevoting, and I can assure you the instances I see an actual moderator (the ones with a diamond next to their name) taking matters into their hands in a given month can be counted in single digits.
I spent an hour looking through them today and I've only seen one false positive and of course someone reported it instantly.
It's pretty useful. One of the questions I saw today was from few years ago and no one had answered it. Someone added a "me too" answer that wasn't helpful. I flagged that answer and provided a new answer to the question, and now it may help someone in the future.