I find it annoying, too. (To make it clear, gender neutral pronouns doesn't annoy me, it's sentences that make me stop and reread them several times to figure out if the 'they' refers to one or several, which changes the meaning of what's going on. I get the same annoyance if I'm reading a scene in which all women or all men are participating and there are random "He" or "She" strewn in, without reference to the character it's supposed to represent.)