Ease of working with for one. I am personally tired of working on mid towers and other similar cases. If its a seal it and forget it case then fine. But if you often are trading out HDD's, adding more memory, swapping CPU's, adding expansion cards, or just have to fiddle around with crap on a semi usual basis, I and I am sure other Full tower users would rather do that work in comfort. Also its about the future, what if I am not a fan of my cooling setup and want a bigger HSF? or its long enough for my Vid card now, but what about my next one? I only have 2 HDD's now but prices going down and capacity going up will that change?
There is no lack of comfort working in this mid tower. I ahve had some that were cramped. But this is not one of them.