So how come BYU doesn't have a day care and a large amount of teachers will not allow children in class?

This seems strange to me. The above comment from Confused seems appropriate; if BYU doesn't have a daycare, and "good" mormons go to BYU, but "good" mormons _also_ have children early, then it almost sounds to me like he's saying that they should choose between an education (which would PROVIDE for the kids) and having children.
I'm hoping that the students will have the good sense to finish their educations and get secure jobs before they even consider marriage, let alone children. I also hope that the trend of young women attending BYU until they are engaged to someone and then dropping out is declining. Point is, young people can make some pretty shortsighted life choices on their own--I really don't feel that their religious leaders should encourage them to rush headlong into parenthood before they've even graduated. Certainly not in the name of God, or anyone else. The Church Handbook does state (last time I knew) that the when and how of many children are brought into the world is strictly between the parents and God. I don't really feel that it's even Nelson's business.
Oh well. Strange planet, full of strange people, long weird trip, etc.

The world is overpopulated.

The responsible thing would be to have only one child, and to wait until one is absolutely ready to care for it responsibly.

But then the church couldn't brag about its numbers.