We already know what we think, the interesting bit is hearing what other people think. Discussion is important. Challenging conceptions is important. Whether we ultimately end up changing or simply reaffirming our opinions, the process we go through, the validation, the testing, the consideration, is what separates the ignorant from the informed, the dumb from the deliberate. Matthew Bischoff, formerly of the New York Times, now of Tumblr, tackles this beautifully on Medium:
I care a lot. Software needs to be criticized to get better. 90% of it is crap, and very few people are willing to explain why. My blog is a place where I can express my opinion, and I have a strong opinion about this "new" product. I share my thoughts with the hope that they'll make people think and encourage discussion, which is exactly what happened.
Our current culture is terrible at this. We watch only the extremist news that agrees with us, we attack not only choices that aren't ours, but the people who make them. We withdraw into what makes us feel comfortable and reaffirms our egos rather than what makes us uncomfortable and enables us to grow.
Being told we're great all the time, in all things, is not only meaningless, it's harmful. Finding vapid intellectual rationalizations or empty, logical validations are likewise worthless and delusion-inducing. The only criticism that helps, that leads to being better, is criticism that challenges, that breaks down, that forces improvement. And that's as true of software as it is of movies, of works of art, of music, and any other craft.
It's what makes all art - and all artists - better.