[mudita]

The German theatre world developed the opposite convention, “Bühne links” (literally "stage left”) means left from the perspective of the audience.

I don’t know so much about the theatre world, I’m a professional dancer, but at least the dance scene is increasingly international, switching fluently between English or German depending on the people present; some people learned the English/international convention, some - especially older - directors know mainly the German convention, some people are not aware that there are different conventions in English and German and the result is complete chaos.