Please note, the question isn't are they bad, it's how much DPS they give up over other ranged builds. I imagine Shuriken expertise is at least mildly helpful now if you get your dex in your 30s and your per attack bonus damage is at least 30% higher than the difference between a shuriken's base damage and that of a different ranged weapon. (Actually... this last bit can't be too hard.)
I just can't figure out the difference in attack speeds between repeaters, bows, and thrown weapons given all the feats and special abilities that impact them.