Well, care to take another look at how the Magicos with a baffle look underneath? And then those without in comparison? You might find out that the baffle helps the ones with a baffle to get a similar outer casing shape to those without (rounded corners, less flat surfaces). It's the manufacturing method of the casing which determines whether you need a baffle or not.
For better understanding, this baffle costs fifty bucks to manufacture, and in a speaker with a market price in the tens of thousands it actually affects the total cost really a chicken dip in relation to the overall cost. If the S series would need one, they would have one.
A slab of ~80 lbs., hard anodized, 3D CNC machined, 6061 T6 aluminum for only $50?? Where do you get your numbers from?
Charles is absolutely right, a curved baffle, is indeed a good, but very costly, feature.