Anyone consider in a real war if we expected GV attacks on our bases, our engineers would use a bulldozer to move back a kill zone, or kill corridors to make defending the base optimal. Other wise our defender's fixed guns are useless, and our GV leaving the VH are often unable to see anything just before they die to an AP sniper round. Or our aircraft to the same sniper round.
For most players time is not their friend in terms of the fun they want to have. Thus the over emphasis on being able to respond from the GV camped airfield. Also upping from a sector away to fly in can mean a lifetime in the damage being done to the field they want to defend, or what will be waiting for them when they arrive heavy alone.
Our fields are peacetime fields decorated with auto and manned gun positions. They are not war time fields designed for battle. The emphasis on player ingenuity and personal combat to defend and capture our fields then is purpose driven. If you want to keep it, or take it, you have to get your kester in the line of fire. A field that can defend itself doesn't need players to defend it.