And it's also bad for the fathers. Why wouldn't you want to spend more time with your kid? You made him/her, after all.
Effectively it does away a implicit pressure that the mother needs to be home and the father needs to work, i.e., the contrary you suggest. Celebration does nothing to help any side of this, if facing reality when bringing up a child. Such improvements for equal chances allow to do that though.
As said, nobody is forced too, if they do want to keep the "old fashioned roles", for whatever reason, sensible or not, they may still do so.