I understand what you mean. You are right, it’s probably something only moderators and admins can see, which is strange to me. Knowing who moderates the forum (if there is a specific moderator) should be easily accessible to everyone from inside a topic.
I searched the Meta Discourse forum and did not find anything meaningful about why this was the case. No one seems to have asked why moderators are not listed in topics for non-moderators or how to switch this feature in for everyone. If you post about this there (http://meta.discourse.org) and get an answer, pls link to it here. I will aim to post about it there, too.