There are plenty of rotors out that have enough material to turn.....the biggest problem is rust! Big rust spots make it hard to create a clean flat surface by machining. Most shops simply do not want to spend time turning rotors when they can slap new ones on in a few minutes and be done.

The biggest problem is the crap replacements.....I replaced rotors twice on my 04 Ram in 60k.....both replacement sets sucked! Hammering again when I said enough and traded it off. Bought a F150.....1st set of brakes lasted 50k and plenty of material to cut the rotors and keep using them.