Originally posted by Aku returns:

I could see it being exploitive if you could level a skill up to 100 in a few hours, but hitting trees, rocks, or whatever takes a lot of time. You could say parking yourself at a greydwarf spawn point and killing everything that pops up is exploitive too.

Nah, actual risk and reward, you have to pay attention, keep buffs up, watch out for adds, time your attacks, and play the game. You can't just afk with the button held down or you'll come back to a dead character and skill loss.