Why do CableCARD host devices still cost so much?

We've been talking about CableCARD long before Engadget HD ever existed -- some might remember HD Beat -- and one thing that hasn't changed in the last five years is that 3rd party host devices still can't access VOD and the cheapest ones aren't cheap at all. TiVo, Moxi and ATI aren't the only ones who find it hard to make the economics of a $300+ device work either, as cable operators around the country have been petitioning the FCC for waivers, arguing that CableCARD set-tops cost to much to deploy. The estimates to add a CableCARD slot to a device vary from between $50 and $100, but either way the prices haven't come down much (if any). Well more recently TiVo has stated the obvious and has requested that the FCC conduct a probe to reveal the reasons. Ultimately the cost is just yet another reason why CableCARD is a failure, but since it's all we've got for now, we might as well try to figure out ways to make it cheaper.