Why are Muslims not open to criticism?

Among all religions in this current time most people are open to listening to contrary ideas about themselves but when it comes to Muslims if there is even a whisper against their Allah then it comes down to violence and killing people or m protests in which they threaten to kill and declare jihad against every Tom, and Harry right from the Pope to America or some poor innocent soul walking in the street!When Pion of the Christ was released (which depicted Jesus of having a wife),Christians who number 2.2 billion people on earth protested but never killed or ranted for someone head like their Muslim counterparts who erupted on something as naive and silly as a "cartoon" ? Most religions are capable of hearing negative views about them and only when you hear negativity do you know how more can you improve.Where are the same muslims when innocent people are killed in the name of Allah? Hardly ever hear any muslim protesting till date on that subject!! Hypocricy is what runs among most of them "not all" and the sooner they change can the world also look towards them with more respect and understanding.For what it seems now,it is just like talking to a "Wall".