Forget all the social and political baggage associated with pronouns these days: Bryan Garner has some thoughts on the subject that are definitely worth reading.
In fact, he argues that the use of the singular they is so ubiquitous these days as to be passé. “What’s new,” he writes, “isn’t the generic pronoun but the referential pronoun.…People are deciding for themselves how they want to be referred to behind their backs—in the third person.”
If you were addressing them directly, he points out, you’d just use you and your. But now “a social movement is behind the idea that people get to decide how references to them should sound when they’re absent.”
Things were so much simpler in the 70s.