Gotta love these threads. Time for conceptual analysis.
As far as I can tell, there are two negative claims about K701. First, that they are unenjoyable headphones. Second, they that are inaccurate (relative to live performances) headphones. And then there is one rejoinder, that headphones preference is (or should be) subjective.
The rejoinder works well enough for the first negative claim about K701. Enjoyment is subjective, therefore the sentences "K701 is enjoyable" and "K701 is unenjoyable" are not propositions (in the Wittgensteinian sense) without the qualifying suffix "to me".
The rejoinder doesn't work with the second negative claim. Similarity to live performances is an objective property. However, one may point out the normative claim slipped in here that accuracy to live performances is a positive property (such that inaccuracy is a negative one). Why should anyone accept this claim?
Now, on to the controversial stuff. One might claim, or try to claim, that concern for accuracy to live performance is part of being an audiophile. That it just is part of the definition and canonical practice of the audiophile community. Sure, it sounds snobbish at first, to say that only people who care about "closeness to live performance" can be considered audiophiles, but I'm not convinced that it's any more snobbish than any other criterion or defining property.
So, where are we? The anti-K701 gang might have a good argument iff a) they can make good the claim that K701 is inaccurate relative to live performances, and b) that can made good the normative claim that accuracy relative to live performances is a good thing (or at least "is a good thing among audiophiles.").