Not that I favour in any manner the infanticide that was China's solution but there are certainly some advantage to preferentially aborting females.

First the female's reproductive potential is limited as compared to the males. Fewer females means a far smaller next generation. And that is not a bad thing given the reality of this planet's current situation.

Secondly a shortage of females might in a generation or two change the balance of power such that females become at least equals. Something they most assuredly are not now.

DA Morgan