"The DSD output is incapable of driving a passive network and then onto a volume control on it's own."
I agree with you, but in the DIYaudio thread people appear to be doing exactly that and saying it sounds good (not that I believe them).
"Even with an easy load the DC it likely to cause problems. True, an inline capacitor can block the DC but that's just like putting in a capacitor anywhere in the signal; it has consequences."
Really??? Exactly what "consequences" are going to occur to the signal you want by cap coupling the DSD? I would expect even DSD 64 to pass right through, say a PPS film cap, without any consequences. It is not like one needs to preserve phase relationships of low frequencies or anything, like one would with an analog signal. I have seen plenty of very good SPDIF transmitter (some of the best actually, if not the best) designs which put a small PPS film cap in series with the signal to block DC.