I've never received for example a s-i-n-g-l-e complaint for being a poor or biased mod during that year when I did my task, and also - for whatever reason - posters (even those I didn't know before) preferred to send a PM to me rather than to an admin when they had problems with being harassed or receiving an unfair in their opinion ban
For the record in my opinion the ban was frequently fair and I expressed it speaking to that offender, and can't really recall a single case they would disagree
(or at least they went trolling elsewhere, not to my PM box anymore). People love being treated seriously and adore transparency, this is so simple.
Maybe an unbiased moderation is not a myth, only a way of approach to your duties and willing to learn about the other backgrounds which you mention? If people volunteer to do this, they surely have time for it.