Titanium is extremely expensive to mill, so are the specialty tools required for working it.
It is also much more time consuming.
As a result of the above the selling price has to be extremely high as well for them to be as profitable as steel actions. Our national economy has been on the skids for nearly four straight years which has resulted in a significant fall in the average person's disposable income so specialty products like Titanium Actions just aren't going to be big sellers.
If they weren't selling enough of them to justify the extra time and cost, then it would be foolish for them to continue making them.