Why does it take so long to get women academics to the top?

Here is the recent research showing that even set targets for universities (research chairs) can’t be met. http://www.theglobeandmail.com/news/politics/canadian-universities-fail-to-meet-diversity-hiring-targets/article29935311/http://www.theglobeandmail.com/news/politics/canadian-universities-fail-to-meet-diversity-hiring-targets/article29935311