It's what people do during their extended masochist rituals.
"Enjoyment is for the weak... I must abuse myself for hours on end in order to attain my powerrrrrrr!!! Then I will pwn j00 all!!! Nyahahaha!"
Ahem, I'm just kidding BTW.
Not that I understand farming or anything, but I'm not gonna knock it.. maybe people have fun in their own ways.