The point is, secular people do not agree that any ideology is above satire, mockery or criticism. If the creators of South Park are willing to put their lives on the line for this principle it reflects only upon the extremism of certain Muslims, not on the secular ideology of West. They haven't done any violence to anyone, yet they might be murdered by Muslims because of something they wrote. Yes, they know it. But that only means that if it happens they will become "martyrs" of the ideology of free speech to us.
I don't agree. The principle of free speech is completely meaningless if people are not allowed to use it if somebody somewhere might be offended. Nobody could say anything. Even Muslims would not be allowed to say anything for fear of being murdered by evolutionists.
Would you rather live in a world where people of conflicting ideologies simply murder each other to shut each other up, or a world where people's opinions are freely expressed and the most convincing argument wins the hearts of the people without any violence, or threat of violence?
In the West, we prefer the latter.