because modern ground-based air defenses are quite good, so that helicopters are deathtraps anywhere close to where there might be opposition, that's why. they're also relatively slow, so you've got plenty of time to react if you detect them. once again, you're better off, saying, mass-producing artillery rockets so they're real cheap and providing them with some guidance, or mass-producing and using weapons like the lancet. the whole point is to find means that let you do what you want to do as simply and cheaply as possible while at the same time minimizing your exposure to danger. this is the age of the missile.
United States