The fact that people can be mistaken, led astray, propagandized, etc. doesn't contradict the original statement that one _should_ counter bad arguments with better arguments. In fact your argument is falling victim to the is-ought fallacy -- Things are a certain way, therefore they shouldn't be another way.

The fact of the matter is that its true that bad arguments _should_ be fought with better arguments; that's a necessary assumption at the base of any philosophic discourse, and doesn't magically disappear when some section of people are disagreeing with you.

It's ironic that you call the OP naive, as your line of thinking leads directly to censorship, and history can attest to where that leads.