Why no remote controlled discrete resistor volume?


I don't get it. It seems that Alps have the remote volume control market cornered. My understanding is that, in general, discrete resistor volume controls (stepped attenuators or relay activated resistors as used by NAT, AN Kits and others) are thought to provide the best sonics (detail, clarity, precision, etc.), followed by potentiometers and then chip controls. If this is true, why have none of the discrete resistor gang (Goldpoint, DACT, Seiden, TKD, etc.) come up with a direct competitor (or drop-in replacement) to the basic Alps remote motorized conductive plastic potentiometer volume control that can be purchased (motor and all) for about $35? These things show up in some highly reviewed preamps with prices approaching $10K and above. It just seems to me there should be better sonic options for remote controlled volume on preamps costing several thousand dollars and up. Why is it so hard to motorize a stepped attenuator? Just curious.
mitch2
How about this http://www.altavistaaudio.com/dact.html using Bent Audio's remote control system.
Byron
The Crystal CS3310 volume control chips are excellent are in many modern preamps and processors - I don't think they deserve third place in your ranking. They may not be better than old school but they technically they are just as good.
http://electronics.dantimax.dk/Kits/Selectors_-_attenuators/index.html

Not exactly "drop-in".
Good question. Potentiometers can add up to 7% distortion to the signal. That's a hell of a lot. Granted, QC goes a long way to avoid that, but what I'd like to know is just what is considered 'acceptable' to the audio community and is it widely known?