I've been thinking about moaning (in the sense of complaining) as a result of taking part in a live discussion on this topic on BBC Radio 4's Woman's Hour last week (listen here - currently misleadingly linked from 'Endometriosis' on the website)...
When people complain that someone else is moaning, this is clearly a put down. But is it fair to call it ad hominem (not in the strict logical sense, but in the widely used sense of 'getting personal')? The anti-moaner usually singles out the tone rather than the content. So Cassandra could have been accused of 'always seeing the negative, going on about the fall of Troy' and the Greens ten years ago who made a big deal about global warming were often disparaged as killjoys always having something to complain about.
What is nasty about moaning is that the negative emotion can be draining...and even contagious, and moaner and listener alike can be sucked into a whirlpool of (often self-indulgent) going on about things that ends in inaction and the bad faith of perceived helplessness where it is easier to complain about things apparently beyond your control than to do something. But it can also be a realistic judgment of the way things are and the last resort of the powerless: their attempt to express their profound disappointment that the world falls short of their dreams. The relentlessly positive can be sentimental fools. The mild moaners bond socially, and have the therapeutic benefits of tension release (even if the tension isn't necessarily coming from the target of the moan). If you accept a hydraulic model, the suppressed aggression of the person who forces him or herself to be positive in the face of obstacles may come out somewhere else...
Philosophers, particularly analytic philosophers, have been trained in what J.S.Mill called 'negative logic' (read my previous comments on this): finding fault with other people's arguments (and sometimes even their own). To outsiders this may look like the relentless negativity of a bunch of moaning minnies...Journalists get accused of the same thing.
Perhaps the Aristotelian mean lies between relentless self-indulgent passive-aggressive negativity and over-optimistic naivity...So moderate moaning, where it doesn't lose touch with reality and become an end in itself, may be part of the good life...