because they are responsible for most of the aim points for an enemy counter force strike. I hadn't thought about this aspect. If you assume your opponent has

because they are responsible for most of the aim points for an enemy counter force strike. I hadn't thought about this aspect. If you assume your opponent has a limited number of missiles (because of treaties and/or intelligence gathering), you build your own missile launchers not only as a weapon system, but as targets to divert incoming missiles away from cities. They can't not target them without leaving a retaliatory capability in place.