I don't for a minute think that Sideshow only cares about money and sales. They do care about the desires of the fans. However, don't poor sales indicate the desires of the fans to a certain extent? Figures from Buffy, Bond, X-Files, Highlander, Apes, etc. remain in stock, often at a 25% mark down. Why, after having such a hard time selling the ones they made, would Sideshow be in a hurry to make more?
I'd expect that the future of Sideshow is in the Star Wars and Lord of the Rings 12" lines. Which line are the fans really getting behind--the ones that sell out in an hour, or a year? Like it or not, sales are a barometer of fan interest.
They might continue, ala Skinner and Krycek, to produce small runs of web exclusive figures in the interest of finishing a line with a sense of completion. That's why we'll see a Giles eventually, and maybe even a Brosnan era "M" someday. (Who could say no to an action figure of Dame Judi Dench?)