Yes, that would be terrible and stupid and the reason GW would probably not have only interceptors capable of engaging fliers.
Since you missed it in my first post: You really think that if GW released fliers, they would not release rules to fight fliers?
Just off the top of my head, from C: SM, Razorbacks can aim straight up with their turrets, hunter-killer missiles and Dreads could be AA as well.
It would require rewritten armylists, but 6th edition are pretty certain to change the army lists anyway.



