I think, Kitty, the problem isn’t that straight people write about gay issues or that white people write about issues relevant to POC etc. The problem is that
women are relegated to writing about “women’s” issues and aren’t given the space to publish on issues of general interest (the Maureen dowd or Caitlin Flanagan effect)
POC aren’t given the space to write about whiteness or when they do, white people studiously avoid reading it (white people don’t even click on articles with “white people” in the title)
And, with the exception of Dan Savage and other more recent columnists, gay people don’t get to write about issues concerning heterosexuals.
So it has to do with power and the assumption of normalcy and the lack of curiosity, as you point out