When's the last time you saw a warrior/ranger/assassin using a +20% while health below 50% weapon? Uh, never? Obviously the reward does not nearly justify the risk...
But what if it were +40% while health is below 50%. Now the risk/reward factor is more appealing - you might see some interesting team builds arise that attempt to keep their warriors at 0-50% for maximum damage output...
Just a thought... why bother having a useless mod when you can have an interesting one?
F