Marketing...
First they selected the 10" version that gives them more favorable results. If they used the 12" versions of each, not only does the W7 have the advantage in Sd, but also in xmax. That is not even considering the W7s much flatter BL curve resulting in less distortion throughout its linear operating range. The 9500 overall would have a SPL advantage because of it's longer xmech, but that might not even be the case of the xmag doesn't allow the sub to utilize that excursion.
Don't get me wrong, the 9500 is a very nice sub and it may come very close to the JL, but don't buy into the specs they list on their site.
