We can always count on Daniel Pipes for an essential and relevant article; thanks for posting.
Philadelphia has a large contingent of African-American Muslims, and I used to see nijab-wearing women fairly frequently.
One reason for its embrace by both men and women, is that it identifies a Muslim woman as "one of ours", for reasons of control by the Muslim community, and for identifying non-Muslim women as acceptable targets for assault and rape. The latter is especially the case in Europe.