All projectiles are worthless in Naruto unless used in conjuction with Genjustu. They only exists to rip cloathing or for the nice *clang clang* sound effect.
Unless the Justu itself is made to amplify said projectiles, they might as well fill their little back-bags up with more useful stuff than kunai's and shurikens. like more Talismens. or heck, if they really want to throw stuff that much, they might as well stick explosive talismens on all them as a regulation from now on. at least Explosions do something. Thats why Ten-Ten sucks. Her entire combat style is based on projectiles. Every time someone dies in the series, its always up-close and personal.(or by a summon, which i'm counting)
Theoretically they should be useful when Sakura throws them because she's got super-strength, but since Sakura herself is pretty much useless it doesn't work out that way.