I believe that what Atmasphere was getting at was not that "the connectivity problem with whatever is downstream" cannot be surmounted, but the fact that doing so turns the phono stage into a "phono stage with a robust enough output stage to be the equivalent of a line stage with a phono stage built in and then with the other stuff that a line stage does taken out."
I don't think he thinks it is impossible at all. I am absolutely confident that Ralph could make a world class standalone phono stage which could drive an amp through a very long cable. That said, as he says, the output stage of that phono stage would resemble his preamp, and I am sure that he thinks that there are very few phono stages out there which have the same ability to drive an amp as the Atmasphere preamps do, and if they do, they might as well stick a switch and a couple of extra inputs and a volume control on it and call itself a full-function preamp.
I think he may have overstated things when he said "I don't see any phono stage that is really designed to do that" because I think there are several designers who do actually stick all that gain stage robustness in there. Saying something like that will almost always provide the opportunity for rebuttal because it's a big wide world out there. But it does not negate the rest of what he said.
What he did not say but may be inferred as his position is also relevant. Having to make two top-notch power supplies and two top-notch output stages just to stick the phono stage into a separate box from the preamp/line stage is an avoidable expense and coloration.
I bet even Dan_Ed thinks that Nick Doshi could probably come up with a "passable" 2-chassis or 4-chassis preamp with the phono stage built in... and it would probably be cheaper to do (and might have fewer chassis) than the combination of a standalone pre and phono.
