Why is NW considered so much higher in %/s than NL?

NW also has 50% ignore resistances, so against bosses with physical resistance they will do 75% damage instead of 50% damage. In other words if the classes did the same DPS, NW would do 50% more dps against bosses with physical resistance. Jump casting allows NW to attack roughly 1.5x as fast as NL. NW's QT is two attacks per skill input, so bats will trigger more often. NW's SP is also considered to be seperate attacks, so each press of QT is 4 attacks with a chance to trigger bats.

The ignore resist and jump attacking are the main reasons why NW grossly outdamages NL on bosses. JoeTang's threads have pretty good explanation on where the numbers come from.