Well putting up a new route with loose rock is different then going to town with a chisel. loose rocks and broken holds are going to happen. completely manufacturing something isn't ok.
So there are cases where it is ok to use a chisel.
The Mohonk Mountain House and the Mohonk Preserve have done a great job protecting the environment thus far, but ... it's all down hill from here http://youtu.be/9AU8fMo8v4k.