So let's assume that men and women are equally good at *everything*. There still wouldn't be 50% female researchers in the top levels because there aren't 50% female in science, as other posters have noted. So just to make explicit the fallout of these kinds of gender quota policies: inferior researchers will be getting posts. This means lower quality research from Canadian universities. That means less research money from global sources and fewer grad students wanting to come here. 
What exactly are our research tax dollars for? The science minister needs to receive a strong and clear message from Canadians: NO!