I've personally rotated my Hemi QC 1500 4x4 wheels 7 times since I've owned it.
I always torque the lugs to 110ft lbs and have never had any issues.
I think that if the lugs aren't torqued evenly to the same specs on each lug, I can see why rotors will warp.
If a person chooses to just tighten the lugs using a bar and not a torque wrench, how do they know if one nut is tightened at 110ft lb and others say at 130 or 95 or 140?
Now that I believe, would cause warping that people are seeing.
Just my 2p. (sorry I'm English lol)