Thinking about this, I think I can see where my brain skips around this.

To me, telling the story is the important part, not making sure that everyone gets a nice representation. In order to tell the story and tell it well, you need good characterization for all the characters, regardless of race/gender/orientation/etc; weak characters make for weak stories, after all. Sometimes telling the story well means not passing this test because the story as written doesn't need to pass the test to get its point across nor to be told well.

I guess what it all boils down to is telling the story, and I'll take into account Bechdel's thoughts on the matter about as much as I'll take into account Jim Davis' thoughts on Mondays.