To claim that certain work is male and certain work is female is sexual discrimination and enables past exploitative practices to continue.
Positive discrimination or affirmative action in favour of one sex implies negative discrimination against the other sex. Will this mean that we invest effort in ensuring that men become 50% of nurses, nurses' aides, cashiers, table attendants, salespeople, teachers of young children and au-pairs ? On the other side, there are very few women who want to be miners, garbage collectors or dockers. A more sensible policy would accept that there are differences between the sexes, and work with reality rather than against it.