Yes, underground bunkers are a good idea, because they keep people safe in times of emergency. The U.S. Department of Defense has an entire building that is built into the side of a mountain. Bunkers are a good way to keep people safe, and make it harder to hurt people in case of a war.
Underground bunkers aren't going to be of very much help if and when you ever need to use them. Your supplies are only going to last for so long, and when you come up to restock, you will be in a completely alien landscape in which you are competing with others for scarce resources. Should it ever come to a situation where we'd need to bunker down, I would rather stand on my front lawn and face the Apocalypse for the 2.5 seconds it takes for my body to be vaporized by the bomb.