It all started with Fanzines. People got a taste for maoning (although to be fair, in those days they had reason to moan). Then along came messageboards and the likes of RCEG moaning about every fúcking thing. If I recall correctly he moaned about the colour of the walls and the fizziness of the beer, and he wasn't even the worst culprit.
It was inevitable that the self-obsessed would find a louder outlet for their solipsistic shrieking.
Some of those kúnts are definitely mentally ill, though.