mbhaub makes an excellent point.
Another obvious one is that most headfi members hail from the US. There is an excellent book by Joseph Horowitz about the trajectory of classical music in the US,
that discusses how Beethoven, Wagner, and Mahler came to dominate US classical music scene.
I am guessing that if we had more members from Europe we would read more about Haendel or Vivaldi, about Bach vocal masterpieces, Italian opera, etc, etc