I imagine that (thoughtfully) moderating a site as large as HN is no easy task, and though I'm all for more transparency, I think logs like that have the potential to open a whole can of worms and add much more burden on Dan. All of a sudden you get a bunch of HN posts that solely exist to criticize Dan's decisions which clog up the feed. If a rule is added against this it looks like even more censorship.
Lobsters [1] has mod logs, but it also has a much smaller community, and it's invite-only so there's less need for moderation in the first place.