I really don't get the consternation. Singular "they" was considered proper English 50 years ago, at least in the NJ public schools I attended. According to the Economist article, it has been used for hundreds of years. As a native speaker of a language in which non-gendered pronouns are normally used even when the gender is known, the insistence on gendered pronouns strikes me as strange. I put it in the same category as insistence on using "one" in stead of indefinite "you" in casual conversation, an affectation I had not come across before arriving at Stanford for law school.