OC, The loss is not for the children.
Prologos, I understand what you are saying about having more time for children when you are older. That is true. Most men over 65 are holding grandchildren on their knee and sharing stories with them - that is a grandfather's role - not a father's.
A child of an elderly parent misses out on the critical role modeling that a younger father can give them. If a father is already retired when their child is born, that child has no exposure to how a male functions in their formative adult years. The child, instead, is taught how to behave in their declining years.
I know men who had elderly fathers - they describe the embarrassment of having their father show up at school and everyone thinking that it was their grandpa. And they describe the disappointment of having a father that was not able to engage in the activities that other children had with their fathers. Other children could engage in activities like 'take your kid to work' days. Simple things like throwing a baseball and learning how to ride a bike were not activities that their elderly fathers were capable of doing with them.
Now, I understand that there are older men with high energy levels...but...not many could run the bases around a baseball diamond and still be able to turn their turn at bat.