It was the strongest (alround) on the PTS. But without the super high crit chances that came with it that were also nerfed there was no need to nerf it.
@Gilliamtherogue did some testing and worked out that he could get higher crit damage from using the warrior than using the shadow.
I'm a little salty because I've run shadow since early release beta, but I guess it can't hurt to finally try a different mundus stone.
They should not have touched shadow or thief mundus, just the crit on gear had to be toned down because +1000 crit was to high and way stronger then + 1000 stam or mag.
Also precise trait they should have left alone.