I was thinking the exact same thing the other day. Lets be honest here, using batarangs to hit your opponent's hand so that they drop their guns isnt really realistic. Especially when those batarangs are as small as Nolan's. I like their design, but honestly, i cant see how Bat-bale could use them. In any case, he should have used some.
Furthermore, the firing scallops on the gauntlets werent so good either. They were mostly a gimmick. It would be impossible to fire those things the way they are positioned. You would have to bend your arm and hope they hit the target, better yet, they dont take an eyeball out! That's why Nolan conviniently used them from such a short distance. But hey....they werent so bad... Its just that he can only use them in a serious manner like he already did, so he wont repeat it.
Anyway, i'd like to see those batarangs enlanged a bit so that bat-bale can use them realistically in the third film. They dont seem like they can break a lightbulb to me.