There's no reason to use a special rock polish set while Genesect is around and does the same thing much better. Also rock polish won't you get very far with no speed investment.
.....wat. Rock is one of the best offensive types because so many things are weak to it, and so few things resist it along with fighting or ground coverage. Despite stone edge's shaky accuracy, it's still a very solid move with high base power and great neutral/SE coverage.Not many pokes are weak to rock/dark. Stone edge misses far too often (i swears its like 60% accuracy).