Not everyone want to get 2 carbs, buy or make linkage, tune them correctly, cut their hood, or has enough engine to take advantage of one.
My car does pull harder and rev more than it did. I can feel the difference. But I mostly installed it for fun. I had dual quads already that worked great on the low dual plane, and had the intake. I agree a single four is simpler, fits under the hood, and would have better off idle transfer. But for what it is, I feel it works really well. And it looks cool!
I'm not saying its better, each intake setup has advantages.