So do you feel that cable DVR's are as innovative and feature rich as DIRECTV or DISH receivers? Even if other companies did make receivers it doesn't mean that either company has to share, or license, their patents to the companies. So we could have a bunch of receivers like the THR22 out there where they don't have features that are standard on the companies current receivers.
There is nothing that has proven that cable cards have done anything to innovate that market. The extremely small % of cable card users is proof enough that it's not a market that companies feel are worth getting into.
the cable co's the min to make cable card work as they made more by renting 5-6+ year old boxes.