It allows more options for those who want to do back-to-back trips. I'm guessing commuters who want more options to do fewer commutes asked for it.

I don't think it's a productivity issues as much as a quality of life issue. If the minimum is 10 hours it sucks for anyone who live in base but has a significant drive, if the minimum is 12 hours it eliminates some rotation combinations and possibly causes more commutes, with a pilot option you can do what you want.

Without any change to the WS/SWP rules you will be flying the same amount of credit per months whether there is a pilot reducible time between rotations or not.