We rarely live in that ideal space in our listening rooms, but that doesn't mean that we shouldn't strive for the more "ideal" instead of starting with a "compromise" as the starting point.
But that exact point was why the QS8's worked so well for 5.1 and 7.1. We don't have a perfect room so the sound that you get from one speaker on one side of the room doesn't mean the other side will produce the same. Think of people with L shaped room, or rooms where the HT is stuck to one side so they effectively only have 3 walls or even 2.
The current Dolby/DTS mode is you have your 5 channels where there is a definate Left, Right, Center and then the around abouts called surrounds. It works in odd rooms as the surrounds are your pretty much large field effects that don't have to have pinpoint accuracy. As soon as you make it required, then you are going to have to spend far more time on making the room perfect in order for the perfect sound to stay that way.
