Then uses the existence of those small differences to justify fundamentally changing their hiring policies.
The latter does not follow from the former.
Again, as with the global warming debate, it makes a lot more sense to tackle the larger influencers first, before addressing these smaller factors.
Even achieving a 30/70 split in a male-dominated industry will help defuse some of the rampant masculinity which passes as social interaction (aka primate chest-beating). Having people around who think differently and don't want to conform to the established practices of pissing contests, dick-measuring and chest thumping will help establish better modes of operation and contribute to better decisions being made (no more buying product X because the saleswoman had huge breasts or the salesman displayed dominant primate behaviour).
Consider a business where 90% of applicants are female and 10% male. If the business chooses to hire 50/50, they are probably getting some sub-par males assuming the distribution of qualifications between male and female for the two sets of applicants are similar (which we don't have much reason to believe they differ much). In this case the females might be annoyed with the "special" treatment given to male hires that perform worse. And male hires might wonder if they got the job because they were well qualified or maybe just because they were male. In my opinion, this kind of "reverse" discrimination perpetuates bitterness and discriminatory thinking on all sides. I don't think of myself as a strongly religious person, but I think Christ had something when he was teaching that an "eye for an eye" was the old way, but the better way to live is to treat others how you want to be treated.
