I have always replaced rotors with new pads too. Have been doing so for many years now. For the customer, its not any cheaper to have a set of rotors turned then it is to replace them. Especially since there isnt a lot of meterial to remove in many of todays rotors to begin with. So they have essentially become a remove and replace item too. Especially if machining them leaves you with a warped rotor shortly after the job is finished.