A good stretch of twisty mountain roads takes the cupping out of the front tire. Am I some anomaly?
I would say so. In my experience, that's what causes the cupping.
Short explanation:
I don't think many of us have such a dramatic disconnect between riding conditions. I think most riders have a more homogeneous blend -- ie: there is little we can do to even out cupping because we are already doing it all along.
Long winded explanation. Skip to the next post unless you are bored:
Discreet blocks of rubber are formed by the tread pattern. Lateral force, as when cornering, causes each tread block to deform slightly, away from the applied force. The deformation forces the leading edge of the block downwards, so as to take the brunt of the wear in the fight against friction -- which is considerable as one leans into a corner. But that's only one of the forces involved.
Remember, we are actually counter-steering slightly as we lean the bike over; applying pressure to the bars in the opposite direction of the actual turn. The bike turns due to the difference in tire circumference from one side of the contact patch to the other. The circumference of the patch near the centre of the tire is longer than the circumference at the outer edge of the patch. Since both are necessarily traveling at the same RPM, the longer circumference travels further than the shorter and so the path of travel becomes an arc towards the side of the tire we are leaning on.
The arc would be perfect if the tire only contacted the road at the point of those two circumferences, but of course, it doesn't. There's a lot of rubber on the road between those two points, introducing a whole lot of complicated interaction. The described arc ends up being more of an average than an ideal arc, and rubber wears away fastest at the points of highest force and friction, forming cupping.
So, back to Art: dramatically changing the wear environment from excessive straight-line riding to a mostly cornering environment shifts the locus of friction. Areas that were previously close to average, near the edge of the straight-line contact patch, are now subject to higher forces; areas that were rarely in contact with the road now start taking a load. The cupping is not reduced -- just shifted further outboard -- but the previous high spots are now worn down and less pronounced.