I would argue that expecting your children to care for you is actually far more egotistic than merely expecting a social safety net for all people to exist.

I did not say that in any means, shape or form. I said that all people need someone to help them when they are old, so all people have some responsibility these "someone". The "someone" are children of people, so society needs people to have children that will become adults and be part of society; all people, if possible (medical conditions are usually the accepted exception).