It is true you can reduce your frequencies on routes you feel are not doing well. But in the process, you hurt your product. Product comprises your frequencies as well as the software like service and inflight products.
Frequency is a very integral part of the product.
I'm not sure if cutting frequencies is the right thing to do in the long run. You are revising your product definition. In the process, when the tide turns, you have a greater task trying to recover traffic. Of course you can, but you would have to resort to lower yields and pricing initiatives. That's not the way we would like to go.