I don't remember reading this either. But then, Nietzsche did straight up call Plato a "bore" :P XD
Seriously though, I think he might have criticized Plato, for Plato differentiated b/w experienced reality (forms) and actual reality but for Nietzsche true reality is whatever is experienced.
Still, quoting him out of context, might not be worth it.
Not sure about Nietzsche but Bertrand Russell traced the ideas of Fascism to the Republic:
Nietzsche always looks uber cool on the surface. Reddit always jokes about how woke teens and edge lords on the Internet get carried away by Nietzsche :P
In one of his books Ecco Homo, he has written chapters on himself titled “why I am so wise”, “why I write such good books” and “why I am destiny”. So taking that into account, Nietzsche might just be the first ever troller in philosophy, and for that he has my utmost respect :P XD
I think Diogenes would be so disheartened and end up trolling you to death if you take away the credit of being the first Philosopher Troller from him. But then again, he is Diogenes. He might let you breathe.
:D