You wrote:
“Who says it is?”
Well, some reputable Jewish historians do. Look at Henry Kamen’s 1998 book called Spanish Inquisition.
You’re wasting your time. Too many people are invested in being victims. The scholarship on the Inquisition tells a very different story from the false one originally propagated by humanists and my fellow Protestants that everyone “knows”. In fact, the common understanding is about as unhistorical as the “flat earth” myth.
Another historical lie is the myth of the “Andalusian Paradise”, according to which everyone in Spain got along and prospered under Mohammedan rule. See, e.g., The Myth of the Andalusian Paradise by
Professor Darío Fernández-Morera here: http://www.mmisi.org/ir/41_02/fernandez-morera.pdf
Morera, interestingly, notes the persecution of Karaite Jews (who rejected authority of the Talmud) by Orthodox Jews in Catholic lands and that at times during the Mohammedan occupation of Spain Jews collaborated with the Mohammedans against the Catholics.
In an adult reading of history, Jews, Christians, and Mohammedans have each been victims and victimizers. The cartoonish narrative that casts certain groups as beyond criticism and others as merely evil oppressors is just an attempt to create guilt so that people today can be manipulated into doing absurd things - Affirmative Action, for example.
. . . some reputable Jewish historians do. Look at Henry Kamen’s 1998 book called Spanish InquisitionKamen was an historical revisionist. WADR, I'll pass.