My guess is that there's a range of braking habits across the field, and perhaps those who practice very hard late braking, transfer more energy into the brakes, or at least put that heat into them in a more concentrated, and repeated fashion.
I wouldn't know if it's enough to fatigue the wheel, but it certainly might push the limits of the brakes, and occasionally send some riders off the road when they cannot slow enough for an upcoming turn.
__________________
Ron - Tucson, AZ