If PC's were soley bound by CPU performance you'd have a point. The point is, APU's are a new strategy for providing affordable balanced performance of CPU and GPU - giving the combined power, enough of both to do what's needed.
Just because there is no Bulldozer based APU now doesn't mean there will never be. Big picture - right now you need a good CPU and a good GPU to have a good all-round PC experience. That product is not Sandy Bridge. The GPU sucks. Llano APU's have enough GPU to deliver mainstream gaming performance, with a powerful quad core. Is it dominating CPU performance? No, but it's platform price is going to be way better.
Think of the big picture and not single, isolated artificial benchmarks and you'll see why AMD's APU's are very strong products.