N.L. at Democracy in America explains why lunar colonization is a terrible idea:

Money can be made without creating a lunar colony, but it seems colonisation in and of itself is Mr Gingrich’s goal. And that presents a problem. We already know that short periods of near-zero gravity are extremely unhealthy for adults. They suffer significant losses in bone density and muscle atrophy after only six months on the space station. How about a lifetime on the low-gravity moon? And what about the children?! The human developmental process is designed for Earth’s gravity, meaning a moon pregnancy would involve serious risks. Any child that survived would be crushed by gravity if they tried to return to the Earth.

At this point one could mutter something about developments in technology that could overcome basic human biology, but even humanity’s mastery of technology cannot overcome the facts. The moon is a cold, airless, lifeless lump of rock a long way away. Only a lunatic would want to raise kids there.

On top of that, there is no need for any of this. Setting up such a colony, besides being bad for the colonists and a massive waste of resources, would serve no real purpose except to serve as a monument to our willingness to embark on useless, costly projects. Then again, Gingrich and his colleagues have shown that they are all too eager to support such projects right here on earth.