I totally understand where arguments along the lines of "automate and eliminate human costs" come from and there is absolutely value in finding ways to simplify/streamline/remove work, and we've developed a lot of custom tools for the site over the years to do just that. It's something that we'll have to do more of now as we transition to the smaller staff, taking a lot from what we've learned over the last several years as guidance.
But the fact that Metafilter has attentive, thoughtful human eyes on the site and hands on the till is a defining part of the culture and nature of the site. It's not a question of whether it's a good business expense, it's a question of whether it's what makes for the kind of community we want to maintain.
I mean, there's groupthink on every site small enough to have recognizable usernames and associated reputations. But the groupthink eventually became too much for me and I left. The actively (and silently) wielded delete button only needed be used a couple of times.
More importantly, an integral part of MeFi's culture is that the moderators aren't just behind the scenes, deleting spam and banning problem users; they try to actively steer discussions away from flamewars/trollbait and towards productive discourse, without being too heavy-handed on the "delete" button. It's similar to what I've seen dang trying to do here over the last few months, but it works a lot better without nested comments.