The first two lines of your observations point out that women are likely to:
-work less overtime
-work fewer weekends
-drop out of the labor force due to pregnancy (diminishing the ROI of education/corporate training investments)
Let's assume that all those points are backed up by statistics.
Then in your next line you seem to criticize managers for displaying a preference towards young single male employees.
But isn't that an entirely rational decision on management's part, to maximize the expected utility it derives from its employees? Assuming all other credentials between a male and female are equal, if the stats backup the assertion that the female employee, say over a timeframe of 5 or 10 years, will deliver fewer hours of productivity compared to the young single male, how can you expect management to take such a risk?
The constant agenda we see is "management styles need to change to accommodate women". Are there any studies or stats demonstrating a net productivity gain from doing so, and what kind of metrics did they use?
I think you make a good point about how women don't respond to the sorts of management techniques that maybe work well on men. But men who find an institution's practices unsatisfactory (whatever that institution is, a workplace, a religion, etc.) often tend to break out on their own, and craft a new organization in their image. Women seem more inclined to complain about the existing institution until it is changed to accommodate them.
So why is it wrong to tell women "Your entire approach to social problem-solving is neither valued nor tolerated in this environment. If you have a issue with that....feel free to go forge your own destiny elsewhere" ? If I said that to a male employee no one would bat an eye. But if I say it to a female employee I'm "poorly emotionally developed"?