Because of the recent terrorist attacks in Paris and San Bernardino, in combination with the over-the-top rhetoric of Donald Trump and other GOP candidates in the presidential primary campaign, Muslims in the United States have been having a pretty rough time of it lately.
But “they” didn’t win because of the way it’s traditionally been used as a plural pronoun. Rather, it won because of the way it’s being now applied as a gender-neutral, singular form that can be applied to either sex.