There is a reason that commercial and noncommercial organisations are so absolutely obsessed with brand management, identity, and reputation, much as I generally find that to be a somewhat absurd concern. Moderators have an absolutely vast impact on how a discussion proceeds, and ultimately on impressions going far beyond just that discussion, including the rest of Reddit (or whatever platform is involved); commercial, social, and political impacts; and the idea of a general online communications themselves.

HN would be a very different place if, say, /u/soccer were mod rather than dang, and I suspect much of its present status and value would be lost in very short order.

We've had plenty of experience, over many decades and much scale, of poorly-functioning moderation, and in general it ends quite poorly. As I've noted many times, one of the most surprising things about HN is that it's retained its status and value as a forum for as long as it has. Far longer than the original and revered Usenet (of which I was a small participant, pre-eternal-September), or Slashdot, Friendster, Digg, or even Reddit (itself a YC launch, slightly pre-dating HN, but unlike HN retaining far less of its original spirit and quality).