I don't think their lawyers are stupid. The women don't want to play on an artificial surface and they took legal advice....they would have been told that sex discrimination is a good way to go as it gets FIFA's attention. Just as race discrimination would. After the Qatar debacle, I have lost all faith in FIFA (though now I think about it, I had no faith before either).
I just think they undermined their own cause by opting to sue while at the same time agreeing to play. How awful can artificial turf really be if only a fraction of the women in the World Cup are complaining about it, and even those women are suing said they're going to play regardless? For most people, I think this is more of an "artificial turf sucks" thing than a gender issue. If it goes to court and they start delving into it as a gender/justice matter it turns the debate. If the women just demand better conditions or they won't play, I think people might get behind them and hope other teams in other sports do the same. But there's a lot less sympathy I think for this as a gender equality issue. Either no one has to put up with it or everyone does. The women are effectively saying that artificial turf is beneath them, but the Super Bowl champion Seattle Seahawks play on it. As do the Sounders, by far the biggest drawing US soccer team. US Captain Clint Dempsey plays on turf. WC hero and the next big hope Deandre Yedlin played on turf. Half the teams in the CFL play on turf. There are lots of people playing lots of sports in all different countries at all different levels and no one likes it but its not a human rights issue.