Well, it could use some improvement BTW
Having no six view at all, like how IL2/FB done it, is clearly an overkill. Makes no sense at all. However, the good thing about Il2/FB was that the pilot is forced to check left rear and right rear sides individually - unlike AH where a single 6 view virtually gives out a panoramic view of the 5, 6, 7 O'c at the same time. (the so-called "Linda Blair" view..)
It does help in increasing the intensity of combat maneuvering, and gives the gamers a taste of why having somebody behind your six was such a bad thing to happen.