I think I understand what they are trying to achieve. Any physical circuit can be malicius and we wouldn't know about it. However, it can't replace itself without the user noticing (You know, opening the case, getting out of the case, replacement in to the case and then closing the case - usually from the outside).
By doing it this way we at least stay where we have been most of the computing history (swapping hardware for better performance). Binary blobs lessens our ability to control the devices we own because it's "circuitry" can be changed on the fly without user noticing (of understanding what really is going on).
I for one think that this is actually clever :) One would assume that programming a free driver for this "controller" chip would be much easier than making a whole firmware blob replacement for each and every device out there. One would also assume that creating a hardware jail to contain all untrusted components would be much more plausible.