Jack, unfortunately the subtleties of modern regietheater seem to escape you. The kilts are of course an ironic comment on the clichés about Scotland (or Scottland) held by the degenerated bourgeoisie. Actually, the director received a phone call "We Muslims in opera are cartoons in nightgowns, as in Entführung aus dem Serail and L'italiana in Algeri. If you not also show Scots in kilts, we will bomb!"