They've been burned in the past by products that were great and got great reviews, but that dealers didn't carry and people didn't buy. And this is a significant departure for them. So I think Wendell's idea here was to get a feeling for whether people wanted this, and at the same time, to introduce their solution to audiophiles, dealers, and the press, all of whom have been skeptical of hybrids in the past -- to demonstrate that they've accomplished something new and achieved the realism of planar bass in a smaller form factor.
(I also think that there are two audiences here -- those who are most interested in real reproduction of acoustical instruments like tympani and double basses will prefer planar bass with its naturalism, while those who listen mostly to rock or are watching movies will prefer the slam of a sealed woofer. But from what I've been reading, the new sub has more slam than planar bass.)
Anyway, transforming this into a production model is a costly and time-consuming endeavor, involving industrial design and production engineering, parts acquisition, and so forth and so they don't want to undertake it if people aren't going to buy it.