I think I understand where you’re coming from, Henrique, but I will respectfully posit that *any* position can be argued from (at least) two sides.
Will all of those arguments be equally defensible morally or factually? Of course not. But they are arguments all the same. I could argue that Pol Pot was a visionary, Hitler saved lives and Che Guevara was a role model. I wouldn’t believe any of my own arguments, but I could put together such arguments.
Think of it as defense counsel in a court of law. The advent of CourtTV (thanks, Nancy Grace!) has shown us all court cases where the “criminal” is obviously guilty. Yet, it’s important — fundamental even — that a criminal defense is presented. Not only does this protect the rights of law-abiding citizens, but it also keeps the prosecution honest and ensures they don’t become lazy — even in a “slam dunk” case. The result is (hopefully) a well-formed argument on both sides and a more-educated populace.
We must be able to perform the mental exercise of arguing alternative viewpoints (regardless how distasteful they may be to us personally). The end result will be a strengthening of our own arguments and, perhaps, an unexpected empathy for the viewpoints of others.