How do you know that Muslims wouldn't do it if there was a longer tradition of free speech and more religions present in the society?
Free speech is often abused, and cannot be policed. After all, who would be suitable to judge what could be said and what couldn't be? If there is no free speech, how can people express themselves on the important issues and have an open dialogue with the goal of effecting change? The bad must be taken with the good.
I think the publishing of the cartoons was very inappropriate, but I hold the newspaper editor and the people involved in creating the cartoons responsible for this crisis. They were the ones with the poor taste and obvious lack of respect, and they are the ones who should apologise and be held accountable.
Many citizens of nations that have a long tradition of free speech are used to it being used for shock value and can easily ignore what they don't like to see, and they do complain as well. This can partially explain why the average Dane probably doesn't see the cartoon issue as being that important.
Anyone here who thinks that the Danish people were at home thinking, "Yeah, the cartoons were great, to hell with all Muslims!" is seriously mislead and devoid of reason.