Admining is more annoying than you think, its all fun to be active for a couple of months, but I can tell you it begins to wear on you. Sooooo many idiots that you have to deal with, you begin to hide from them. No matter decision you take, there is always someone making a drama thread about their ban, or hating you in future. I dont say I do a perfect job, but I watch admin chat when Im not grabbing a drink; and I stop any flamers with mutes, and tkers with short bans. More admins are probably need, but they will become old and crusty like the rest of us in short order.
EDIT: Also who do you think does all the name changes? :p They pile up more quickly than you can believe.
Yes, today I set out to clear some of the ban requests, I got through five before the first one started messaging me complaining about it, I managed 6 I think before I was inundated trying to explain the rules and reasoning behind why someone was banned and someone else wasn't. We make mistakes too, we can't catch everything and sometimes the evidence is staged so we have to account for these things.
I noticed a ban that I put through just under a year ago, it expires on the 6th of January 2013, my first essay bans (it was a pair) and that means that I have been an admin for over a year and two/three months, I can't imagine what it's like for the poor buggers who were admins before me since people don't "forgive and forget" or even pretend to understand why they were banned, they hold grudges, those mount up and you have more people to deal with, scrutinising your decision making and I can tell you that makes you think.
No one wants to be disliked and that can be rather draining so it's no wonder that sometimes people take breaks and keep their heads down until it's absolutely necessary.
That's just another possible reason and of course, not everyone has the free time all the time. Anyway, enough excuse making.
Oh, and I disagree that this thread is useless, it shows concerns of a community, whether a few members or not it still has a valid place.
EDIT: Heh, I just re-read one of your previous posts Leshma "Too nice to be an admin" - It's good to be a bastard I suppose but I don't think being nice is a bad thing, being assertive but putting things nicely without an air of arrogance or misplaced "authority" is the better way to do things. Civil is the word I'd use.