But to do that they have to consider and then discriminate using the gender of their applicants. The position in your example seems to be that two wrongs make a right - discrimination favored men at some point and so discriminating against men in the hiring practice is reasonable.

I strongly disagree with that position - as far as is possible that conversation has been had and settled; companies shouldn't be discriminating on gender. I dunno what the law in California is but my stance is that discriminating on gender should be illegal. Even if the people doing the discriminating might feel they have a moral right to it :P.