not really seeing the reason behind this besides lowering multi dotting damage, but did that really matter? and if thats the reason for the nerf why touch devouring plague... and mastery nerf too? : /
the only upside i can see is a mind blast/mind flay and shadow word death could increase shadows burst when MSx3>MB>SWDx2
but really dotting and kiting is the reality alot of the time soo... : /