Imagine your students are seated in rows of desks. Two groups will fall naturally under your gaze: the students in the front row, and those in a column through the middle of the room. That’s your T. By default, you will call on those students more often, give them more of your eye contact and attention, notice more quickly when they’re dozing off or misbehaving, because they’re in the places you will most commonly look. Students on the sides of the room and at the back, by contrast, will be neglected. In order to counteract this bias and be a good teacher, you have to remind yourself to look outside the T, to keep the entire room in your mind and distribute your attention equally.
The publishing industry — really, society at large — is a classroom with assigned seating. And you, the reader, didn’t assign it. Somebody else decided to stack the front row and that center column with mostly straight white guys: to give them more in-house backing, more marketing support, more reviews in major outlets. If you let your gaze rest in the default spot, those guys are the majority of the ones you’ll see. And they may have good things to say! Excellent contributions to the class! . . . but so may the students who have been relegated to the sides and back of the room. The ones you’ll wind up ignoring, if you aren’t conscious of the problem and taking steps to counteract it.
–Marie Brennan on reading outside the T.
Brennan’s point is against that “no it is YOU who is the one who is the racist/sexist/whatever!!!” argument certain sectors like to make whenever anyone does something like, say, proposing a year of not reading books by straight white men.