I believe that the free interaction of ideas is invaluable to society. Suppressing dissent isn't just bad because it helps a government maintain a monopoly on power. It's bad because it creates an intellectual monoculture, and a monoculture is extremely vulnerable. Without exposure to a robust culture of debate and discussion, people are far more vulnerable to manipulation by the next great demagogue or by their country's propaganda or by their opinionated uncle. Citizens in a free nation need to learn to weigh ideas and discard the bad ones, and we build that capability by exposing people to many ideas, both good and bad.
If we continue this trend of suppressing any views that are distant from the mainstream, our ability to judge ideas will atrophy. We'll be doing the intellectual equivalent of becoming a couch potato: by never allowing ourselves to hear a narrative we dislike, we lose the ability to judge right and wrong for ourselves. We sacrifice our own judgement and replace it with the shifting tides of conventional morality.
In Fahrenheit 451, Faber (the covert intellectual) says this to Montag as his captain finishes defending their acts of censorship (book burning):
> All right, he's had his say. You must take it in. I'll say my say, too, in the next few hours. And you'll take it in. And you'll try to judge them and make your decision as to which way to jump, or fall. But I want it to be your decision, not mine, and not the Captain's. But remember that the Captain belongs to the most dangerous enemy of truth and freedom, the solid unmoving cattle of the majority. Oh, God, the terrible tyranny of the majority. We all have our harps to play. And it's up to you now to know with which ear you'll listen.