Somehow, until I recently read a New York Times obituary for Kate Swift, I'd been unaware there was such a thing as The Handbook of Nonsexist Writing. But there is. And it's lots of fun if you think women are people, as the cartoon illustrates.
I particularly like the section on what Swift and co-author Casey Miller call "The Pronoun Problem."
In 1850 Parliament got into the act, passing a law that "words importing [signifying] the masculine gender shall be deemed and taken to include females." Perhaps so, as a matter of law, but speakers of English have never quite bought it, say Miller and Swift.
So precise writers quite commonly use they as a singular, to indicate they are speaking of both men and women. Miller and Swift provide nearly a page of examples from the works of people no one doubts write proper English.
I've long used they and them as gender inclusive singular pronouns. Now I've got a couple of accomplished grammarians to back me up. Most of us do this in speech. If enough of us insist on the usage in writing, perhaps we can get rid of the sexist grammatical prejudice against this usage.
There, I've got a new campaign.