I thought, "aMule menu" meant the options dialog which imho every user should open while the first run, so setting this would be no problem.
You could ask the same about the Message Filter. Why do we have one, if it's not activated? Because everyone that wants to CAN activate it, and every user that doensn't care has no change.
But in fact I don't see a problem of having aMule and WoW running caused by CPU, this is more a bandwidth problem which can already be affected by the user.