Well, I get your point! BUT, we are talking about saving ONE life and in exchange jeopardize the entire galaxy, if not the universe. AND saving her/ or him means that you have formed some form of attachment, which IS forbidden for Jedi.
Regardless weather Obi knows Padmé is alive or not, he also points out to Anakin, if they should capture Dooku at that moment the war might have ended right there. "We have a job to do [...] what do you think Padmé would do if she were in your position?" - Obi. "She would do her duty"- Ani.