And that doesn't address the entire first part here:
> The moderation team is disempowered to ban people for driving away many more contributors worth of time than they have contributed themselves
The contributor-hour estimation doesn't exist. (I struggle to imagine how it even could.) It's a rationalization which has come up because the most prominent person they want to ban is a consistent, prolific, long-time contributor and they need to say something to make it seem like his participation is a loss for the community as a whole.
It seems like what they really want is arbitrary bans of political opponents.