No. Look at the top 1000 world strongest people. They're all men. Men and women and physically different (including our brains). It's not sexism that causes the strongest people to all be men, it's just physiology - men just have bigger muscles than women. But when the majority of engineers are male instead of saying "well I suppose the male brain is better suited for engineering tasks" cries of "sexism!" are made. To accuse an organization of sexism you have to find evidence of it (the proportion of females in the workforce is not evidence).
It'd be like taking a count of all the letters used in Slashdot posts. a = 23,345,494, b = 12,342,463 etc, and then coming to the conclusion that Slashdot is letterist against the letter 'x' because it's used the least - the underlying belief being that "in any fair system, all letters would be used the same amount". This isn't true. It isn't true of men and women either.