What about someone who argues "Rape victims don't matter because they are just women, and women's feelings are not important"

That isn't something that can be argued against with facts. You can't present evidence to counter this, because they didn't use facts to come to the opinion. As the saying goes, "You can't reason someone out of a position they didn't reason themselves into"

There are a certain class of opinions that we need to be able to dismiss with just a "that is just not worthy of even talking about." While I believe this list of things should be very small, it DOES exist.