Let's not get caught up on what dead ancestors may think. The world is already overpopulated. Overpopulation causes depletion of natural resources, degradation of the environment, conflicts and wars caused by such lack of resources, and there being less resources per capita. Adding people when it is causing problems like these is harmful.

However, people having 2 or 3 or thereabouts children isn't something to be worried about too much, so go ahead if you want to. But people who have lots of children has to stop. This is per person, so it includes men who have children with different partners. If it is left too late, then less can be done about it.