If you go to Penchum's profile and note his gear list, you'll see that your logic directly threatens his psychic existence.
See COLLECTING: An Unruly Passion - Psychological Perspectives, by Werner Muensterberger.
You have to separate out those who are at Head-Fi for the music, from those who are here for the gear - for any kind of loose rationalization that will justify the purchase of yet another piece of equipment.
pp, you represent Janine Chasseguet-Smirgel's "isolated individual who ego has not delegated its reality testing function to the group" (Head-Fi, in this case) - to what she calls "the incense bearers of illusion." That's why Penchum cites that you cannot win that argument; that's what he hopes and prays, at least. He hopes to keep Head-Fi ideologically pure, even if that ideology is not strictly true and accurate and even if it costs people a lot of time, money, and frustration as they compare what they really are hearing with what the senior addicts here TELL them that they're hearing.
J. C-S. says, on p. 157 of THE EGO IDEAL, that (in this case, people here at Head-Fi are) "the child showing himself to the observer with his newly realized acquisitions" (headphone amps, in this case). Just look at all the posts with pictures! If you deny these gearhead children their pleasures - and remember, they now firmly run Head-Fi - they will squall. And you can see why.
Ideally, music lovers and not obsessed gear people would run this place. But that's an ideal world.
In the meantime, I can attest to your ears.
I spent last winter listening to the resistored-down headphone jack that comes standard on a Denon integrated and, yes, many receiver/integrated headphone outs are delicious. And lots of dedicated amps suck by comparison. But if that were accepted, how would people get to play with tubes and tube roll? How would they guiltily sneak yet one more piece of gear past the (if they happen to still be married) wife? Etc.
Dedicated amps are not a panacea.