I don't think that was a cheap point Wolfgang was making there, and he put it in context. Racism can creep into any set of people, and it's important to be prepared to oppose it and expose it anywhere it crops up, because we should recognise it as our common enemy, whoever we are, and whatever we believe abvout anything else.

The same is true of its variant, sectarianism, and that can sneak up on people in traditions that may with some reason pride themselves on being racially inclusive, such as Islam or Catholicism. (Some reason, becausde members of both traditions can fall down badly on that too.)
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This thread reminded me of the old Northen Ireland joke: "Are you a Catholic or a Protestant?" "I'm an atheist/ a Jew / a Muslim." "But are you a Catholic atheist/ Jew / Muslim or a Protestant atheist/ Jew / Muslim ?"