Yes, it is a bad sign when an individual feels no desire to fatherhood or motherhood. It doesn't have to be biological, but it is what we're built for.

I've talked to many people my age who say they have no desire for children, or who say they don't like children. I think that is a symptom of an increasingly childless society. Fatherhood or motherhood is inconceivable when you haven't spent any time with small children as an adult.