I gather that the strict policy stopped in the postwar period in Japan because there simply happened to be a cloth shortage. People were turning up to classes in expensive silk hakama that had belonged to their Grandfathers and destroying the knees.
Where the hakama has become a status symbol, the root of the problem actually lies somewhere beyond the hakama. If it wasn't the hakama, it'd be a black belt in that situation, or simply being able to say "I'm yudansha."
andrew