The problem with PMing a moderator is that the issue may be an issue that others also have but they will never know if the complainant keeps it private.
While I do agree to some extent; it can also go the other way. You can get some who just pile on, even though it was never really a problem for them until someone else decided that it was a problem.
And since airing in public can be done anonymously but airing in private cannot, those that are unwilling to express themselves honestly without leaving their name cannot do it via PM.
Actually that's a luxury that it not available on most forums. We're one of the few that strives quite hard to keep guest posting available; despite the best efforts of the spammers and a few rouge posters. And while I hope that it never does go away; as long as there are determined spammers it could still disappear one day sadly.
Besides, posting as a guest doesn't totally conceal your identity.
And as a moderator, no matter how often you state your fairness, there is no way you are going to forget that a person stated that you were part of (or all of) a problem instead of part of the solution. It's human nature. How many times have you read about people who bring up issues privately and they never get resolved? Then when they are publicized, the issue is fixed but sometime after those that complained (even privately) somehow lose their job due to some generic excuse.
While all you say here is true, things are very different when it is your job & livelihood at stake. Since no one on staff makes a dime, including me, for their efforts it changes things quite a bit. At worst, a staff member leaves or is asked to leave, and there might be some hurt feelings or bruised egos. But no one's financial well being is hanging in the balance.
As for resolving the issue, the issue will always be resolved; it just may not be resolved to the person making the complaint's satisfaction and that won't change whether the complaint was made publicly or privately. In fact, in a borderline situation, a public complaint is far more likely to see me deciding to the disfavor of the complainant.
I don't think that moderators have their authority undermined by open complaints. It gives them a chance to openly show they are willing to address issues that can fester. That enhances authority. Do you think that your having to answer issues publicly above has hurt your authority?
We will have to agree to disagree on this point; sorry! But I see it as publicly criticizing the staff member in public and that can indeed lead to undermining their authority. Furthermore, I believe that it can encourage further complaints if people see their successes.
As for my authority; since there is no place higher to appeal, no, it doesn't hurt me. Other staff members can try to convince me that I was wrong and get me to change my mind; but again, no one else can overrule me. And that changes things.
A separate forum for addressing internal issues publicly.
Well, if one still chooses to go public, there is already a forum for issues of any type with the forum. Which is where frankly I should move this topic, but for now I've left here in the forum where most people visit so that it gets maximum exposure.
Ability to anonymously PM moderators.
Sadly, not an option. The forum software simply doesn't support that possibility. In fact, guests have no access to the PM system at all.
An assurance that if someone has an issue with one moderator that they can PM another moderator and be assured that their name would not be revealed.
Already happens. I don't always tell the staff member who contacted me; especially if they request that I don't. I would hope that the rest of the staff would also honor that request, and in fact this post can serve as direction that they should do their level best to honor any such request. Of course, depending on the issue and nature of the complaint, it may well be possible for them to guess who complained.
And if you feel that you are being unfairly targeted after making a complaint, or for any other reason, again you are always welcome to contact me.
