Honestly, why do men (and in fact, women) worry so much at the thought of a beautiful human being knocking on their door (likely to be in their 20s and 30s) to say hello?!!!?! Is it that bad to offer life?!! And offer a childless helpless couple the chance of parenthood?!!!! geez louise! I'm braver than that...and thank God my egg donor friend-of-a-friend is too!!!!!!! Blessed are the selfless.
It's not so much selfishness, I think. Some men may prefer to stay anonymous so there's no conflict with the birth parents when their child tracks him down, for example. Maybe they don't realise they have any responsibility to the child.

They're not saying they don't want to help unable-to-conceive couples, they just don't want anything to do with the baby after their bit is done. Some might, I know if I donated my eggs I'd want it to be to a friend or family member.

I think there should maybe be an option to say "no, I don't want to be tracked down" and that information made available to the birth parents when they choose their donor.