In the past, if a man had a dalliance with with a woman and she got pregnant, he was expected to marry her.
Now we expect women to have to be responsible for their own decisions the way men are, but women are generally more emotionally vulnerable than men, due to their more compassionate and less aggressive personalities, and are more easily manipulated as a result.
Therefore it may be up to men to not abuse that.
This was the assumption in place in the past, which is why young women often had chaperones present during close interactions with men, and why the 'marriage if pregnancy' responsibility was placed on men.
We've tried the 'rawr girl power, women can do everything men can do' culture, and the result is scores of women being used and taken advantage of because they were not capable, emotionally/temperamentally, to be their own advocate in sex and dating interactions.