If every male approached the situation mindful of the responsibilities of both parties that you point out there would be far fewer abortions IMO.
That said, there is no other practical way to legislate other than to put the decision in the hands of one person. The one person that makes the most sense is the mother, for biological and other reasons. Once she realizes she is pregnant her world changes immediately and drastically. A man's doesn't.
In a mature relationship many women are going to have a discussion with her doctor and those closest to her. But those discussions may be colored by emotions and value systems that may be different from hers, and some maybe even contrary to her very own interests.
Men should be educated that their responsibility begins prior to the sexual act and doesn't waver regardless of what happens in the span between 0-9 months. It may not be "fair" that men lose decision-making control during that timeframe. But this lack of fairness pales in comparison to the potential lack of fairness a woman may experience during the same timeframe and afterwards.