Jovanka Houska, writing for Chess.com:
Originally, the world championship was scheduled to be held at the end of the 2016 but with no bidders in sight and afraid that the event would be cancelled, FIDE made the decision at the Baku Olympiad to award the event to Tehran, Iran.
While Iran is a country rich in chess history, where chess currently enjoys a huge surge in popularity, there are some drawbacks to such a country hosting a female chess event—the glaringly obvious being that countries such as the U.S. had advised their citizens not to travel there and that females are forced to cover their heads.
This posed an unenviable dilemma for the qualifiers: Should they refuse to play and miss out on the chance of a lifetime and perhaps hinder women’s opportunities in Iran? Or choose to play and compromise their own values of gender equality and security?
Notice that: forced to cover their heads. FIDE should not have decided to award the event to Iran. Not to a country that doesn’t treat women as equals. Not to one that forces hijabs.