You've proved exactly the point I was trying, perhaps unsuccessfully, to make - that by allowing others to air their views, you allow them the opportunity to condemn themselves by their own words. If you simply stifle them, you don't change anything - they still hold their, perhaps odious, views and are neither deflected from their purpose nor persuaded of their error (in fact, it may very we'll serve to reinforce their opinions by virtue of giving them a sense that they are somehow the victim).