I would believe most parents would agree with you that you shouldn't have a child if you can't ensure their safety.
Most parents, if queried, would probably agree. But most parents, in actual fact, would probably not hold back on such grounds. About 100% of children born today are born without reasonable safety guarantees, and are very likely to die at a young age.
bringing another child into the world you know to die would be morally questionable at best
Morals and procreation are rather mightily disconnected in the human case - it takes something the magnitude of religion to connect them, and that's very seldom related to the rights or well-being of the child in any way. Perhaps Data wants to be human in this respect as well?
Although Data probably doesn't see any hurry. We could just as well ask why he stopped dating after "In Theory". Being an android, he'd simply still have plenty of time to break all of Casanova's records, even counting in his apparent "aging subroutine".