This thread really start to go nowhere...
We can resume this:

-Sange is the less efficient of Ninja merits.
-Shurikens cost a lot to make and stack of 12 are not efficient.
-Math proved than best shuriken with best setup cannot be more efficient then melee with basic cheap gear.
-Some people want some attention.
-People who play game for fun will play WHM/WAR to be DD aren't useless but just less effiecient.