a few comments:
actually that's not true (although they are certainly used that way), airshocks are designed to make it possible to to put he rear at the proper ride height when carrying a load - like you fill the car up to go off on vacation for 2 weeks, or in our case putting 3 rear end housings and four rear end pigs in the trunk to go to the swap meet. This allows you to put the car in a position that the whole suspension works properly compared to having the *** end dragging and the front end pointing at the sky. Of course there are those who might overdo it and go in the other direction like was popular in the 70s