Even when volume is matched, there is unacceptable loss of dynamics when the digital volume attenuator is used. It is a flaw of the technology, and is not dependent upon the number of power supplies. Apparently, those last couple of bits really matter. Luckily, it can be bypassed. The series 9 has six independent power supplies per channel, and suffers the same fate with volume.
If people like their unit without a preamp, then great. They also should know that they may like it even better with a good preamp.