Submitted article is saying that she should have taken more maternity leave in order to make it culturally acceptable within Yahoo for other parents to take that leave. (That's a good point, and is probably true.)

But if she had taken more leave we'd have had a bunch of articles saying why she's terrible for taking that much leave.

The future people will want to know why her PR is so terrible; and will be able to see a bit more clearly whether what she did was useful or not.