The first is that the price is right; you can get JBL clones for 1/3 the price of JBLSecond is that there ain't a lot of 1.5" throat horns around, very few actually and P.Audio has most of them
Third reason is that the baby cheek thing seems to work well up close, as opposed to the PA CD types, although the 1.5" P.Audio at 12" X 12" looks more like Jessica Alba's ass than a baby's.