It hurts your country's ability to leverage foreign minds when you begin to censor the outside world. Plus, with the internet, censorship becomes really impractical. China and North Korea don't do this completely successfully and they spend a lot of effort to keep their citizens on some form of lock down. So not only do you end up missing out on the collective conscience of foreigners, but you also lose some portion of your own population's trust and creativity.
Meanwhile, the rest of the world is working together to solve problems in an open, concerted manner. I'm not saying our world is perfect but I think it's fairly obvious that censorship, in the days of the internet, is not the right way to the future.
We need to get over ourselves, stop being so sensitive, and recognize that even when governments make laws to protect people's feelings, people will still say mean and negative things. I don't want to read those garbage comments here on HN because it fills up the thread, but I can tolerate them in the real world because I know I can just walk away. The only time speech should be regulated is when it incites violence, and I'm sorry to all the extremist Muslims, but drawing a picture is not viewed as inciting violence by most of the world, including most of the people who follow similar forms of that faith.