The problem with rocket trucks, and the very reason we will never see them, is this:
They are large area saturation weapons. They are beyond visual range weapons. They are not precise. Hell I doubt you could even land them on a city from 5 miles away, in AH.
So little Timmy takes out his rocket truck (pays extra perks for the trailer, too!) and goes a'-driving.. he drives... and drives.. and drives.. he takes a nap, takes a leak, goes out to eat, comes back finds he's still only half way to his target spot... so he drives and drives.. and finally arrives at a spot that will get him in range of an enemy field's city. So he "sets up" -- which is refreshingly breif after the long trip there, and gets ready... and.. and... FIRE!!! WHOOOOOSH.... um.. wtf? That's it? Big whoop. Screw this game I'm going to play WW2OL!!!!
Poor little Timmy doesn't like the way that gameplay goes. If you can't see it, and if you can't get a direct aim on something, chances are we won't get it in AH. AH is not about saturation bombing from rocket trucks beyond visual range. That's also why we'll never get the V1 or V2 buzz bombs. It's not what AH is about. If you want an individual victory (be it against buildings or other players) you have to find them, target them, kill them, all while going into harm's way. Frankly, rocket trucks won't bring the returns required (direct feedback), and the costs are far too high for much use out of the thing. Hell a tiger in an enemy city is better than a rocket truck. At least you can see things in the tiger, and you're pretty well protected.