Sperm Donation from the Perspective of a New Parent

With my own son on the way, I find it even more difficult now to understand how an egg/sperm donor can accept money in exchange for creating a child and relinqushing contact. From the moment I found out about my pregnancy, I felt protective of my baby and I developed an enormous attachment to him. While I am at peace with my own situation, that is only because I did everything humanly possible to locate my biological father and offer him the opportunity to know me. I strongly suspect that he knows of my existence from my efforts, but either does not care or has other obligations that outweigh me. So why put emotional energy into someone who does not want involvement in my life? Not only is he missing out on the chance to know his daughter, but now he'll likely never know his grandson as well. If he changes his mind, it's up to him to find me.