Shears have 4 uses, according to Jeb. They shear sheep (and destroy wool blocks faster), they cut leaves (possibly meaning we can collect and plant leaf blocks), they diffuse TNT and there's a fourth use that he says is a secret.
Still, how many times is one going to use them or have a need for them other than that one time? It's like axes. I rather use my fists than use axes because you can't break them. Well, not in Minecraft anyway.