Sad to say, but anything that reveals Catholicism in a bad light offends Catholics.
There's a difference between being offended, and in trying to set the record straight. There have been a ton of recent studies on this time period using the actual records of this time that show the Inquisition wasn't all what we have been led to believe. But willful prejudice runs deep, and some people prefer to hang on to salacious myths and "Black Legends" rather than come up to speed on the actual history based on documented facts.