The Myth of Over-population

I encountered this idea in college a lot. Whenever I said I wanted to have a larger than average family, (4+), many people, usually professors, always tried to argue me into the "world is overpopulated" myth. They seemed to think it was selfish of me to bring more people into this world than just enough to replace my husband and I. That so many people would unfairly suck up too many natural resources.
I always tried to express my desire to be frugal, and not live in excess. They didn't seem to see the connection.
I mean think about it--you want to point a finger at someone who has several children for using too many resources that other people could be using. Well, if that family is extremely extravagant and wasteful, perhaps that is justified (maybe). However, what about celebrities like Tom Cruise(sp?--sorry, I don't follow Hollywood that much), who own massive, excessive mansions, and employ all kinds of household and grounds help?? It seems to me that people with several children are frequently lambasted in this way, and yet no one seems to apply the same principal to people who just live in wasteful extravagant ways, who have few or no children. My ceramics prof and I used to argue about this a lot. He wasn't married and had no children, yet lived in a large three bedroom house, all by himself. Is that not wasteful?? Could he not find something more suitable to his meager needs as a bachelor??
You take even the Duggar family. I know they have recently built a very large house that has lots of amenities that many of us don't have. However, when you check out their family website, the boys and girls don't all have their own rooms--they share rooms. They share closets. They cook their own food. Yes, their house is lovely, and very large, but they also share all the work, and probably all contribute to the household in some way. I would imagine that if you looked at the same number of children spread over several American households, there would be more spent total on those children, than all those children in the Duggar household. Also, they have waited and waited and saved and saved and it took years for them to build this big beautiful house. Remember, they do have grown children!!
Yes, my own family is growing. Yes, I would love to have a larger house--someday. I would love to have a spread of property for us to work on, play on, and grow on. But I guarantee that we will do it incrementally, and as frugally as possible. You don't spend the first seven years of marriage getting out of debt, only to pile it back on aimlessly!!