Missile Defense Divisions

Are Missile Defense Divisions useless? They are not mobile units, so they don't act to attacks near them. Which means they can only be used for decoys, but no one would be dumb enough to attack them, so can someone tell me the purpose of them? If there is no purpose they should be removed.

well i dont think many people use the default weapons that are put in the missile defense divisions.... usually they will pick it for the name and the number of weapons allowed in the unit..... a unit of defensive batts MIBS and AAMB would be useful for blocking and painting and could be appropriately named a missile defense division