Unfortunately I'm at a loss as to being able to find origin of the quote, and therefore can't shed any light on its original context. I think it's unlikely that such a small, widely distributed fragment would come from Nietzsche's Nachlass. If I was to guess I would say it's from a section in the work of another philosopher who has made their own translation from German. When compared with Kaufmann and Hollingdale, Krell's translations in Heidegger's Nietzsche are a great example just this. But that's only a guess.
From Beyond Good and Evil onward Nietzsche held tight to the association between philosophy and biography. Every philosophy amounts to an unconscious confession on behalf of its author. It reveals more about the internal configuration of drives within the philosopher than it does about the phenomena that their philosophy attempts to address. I suspect that this is the context in which you use the word 'symptomatic'? - That the selective use of a fragment from unknown origins reveals something about the author which is in a way above or aside from the explicit content of the passage in which it's included?
So secondarily I'd also be curious about others' thoughts on the
political aspect of the "reading" (or its absence) of Nietzsche which
is implied in these sorts of non-specified citations -- i.e., I'm
thinking that perhaps in this light the multiplicity of different
enterprises exploiting the quote take on another aspect entirely; of
disastrously obscuring the "real" potential for Nietzsche's philosophy
to transform our discourses and disciplines -- to "really" change the
I think there is a great deal to be said in philosophy in general regarding 'cherry picking'. I admire the phrasing where you talk about 'real potential', instead of simply chastising these various approaches for missing the mark of allowing the real 'in itself' or one true meaning of Nietzsche's passages to permeate their work. Although perspective is the ultimate horizon for Nietzsche, I think there remains an ambiguous line between creating a caricature of Nietzsche, mistaking Zarathustra for his ape; and the productive power of misreading, or reading against pre-established exegetic wisdom.
Does the misreading have to be deliberate, as was the case with Gilles Deleuze, in order to "really change the world"? I remember reading an interview with Foucault regarding the French orientation to Nietzsche which emerged through philosophers such as Klossowski, Jean Wahl, Geuroult, Deleuze, Foucault, and others, (for eg. those who attended the 1964 Nietzsche conference in Royaumont). His comment was that the thing these philosophers had in common, was that they accepted that a genuine fidelity to the core of Nietzsche's work was not to treat it as an edifice which should be interpreted 'correctly'. Rather, this fidelity consisted in inhabiting particular perspectives in such a way that it pushes things further, seeing through their conceptual lenses with strong, rabid, crazy eyes; tearing it from its native conditions of emergence to see how it fairs at the delirious heights of Dionysian affirmation. Undoubtedly not all the authors in each discipline you mention are doing this. But the point would be that it is less a question of 'does their use of this quote accurately reflect its original context?', than - 'what new things does it bring to pass?'