I would assume TPTB saying X is more probable than belief saying Y since the devs should have access to sales data.
While it may look like Davion sells the most for us commoners, it doesn't mean it is so. Maybe it was once true, and not anymore.
Either way, i figure poor sales of a series indicate it is not a good idea to continue. Sure, yet another book made the same way could turn into profit... but it is not probable, merely possible, and "merely possible" isn't probably good enough, whether one wishes it so or not.