Indiscriminate sandblasting could be the root cause of some wheel failures. Heavy blasting work hardens the steel and can make it brittle. Oxidation has the same effect chemically and put the two together and it can be trouble. A severely corroded wheel that is heavily blasted will look clean, but will have a hardened surface with oxidation remaining in the nooks and crannies that the sand missed. Such wheels would fail regardless of the tire type. I contend the greater grip provided by the more uniform radial tire contact patch is the reason that radial tires 'break wheels'. Bias ply tires, on the other hand, will break traction and put the car in the ditch, sparing the wheel. Most likely any wheel that failed with a radial tire mounted was unsafe to begin with.