Important caveat: telling a person their ideology is hateful isn't "an attack," and letting them continue to wallow in ignorance is more unkind than enlightening them.

That they feel attacked is another issue. We still have to deal with the consequences of this, and should be cognizant of it, but at the end of the day let us not lose the plot and start conflating their sensitivity with offensive language as if they weren't two very different things.