Movies are an art form and as such they must represent the vision of the artists involved whether or not the entire audience morally approves of what they represent. If an artist's vision involves scenes of gore then that should be allowed to be shown in a movie. Gore makes most people uncomfortable and is a way for a director to connect a film intensely to its audience. There are many great paintings on the walls of museums that depict scenes of extreme gore but they are still considered highly regarded fine works of art.
Theres is no hard evidence to support the fact that watching gory movies makes a normal person commit real violent acts. Most people know how to discern fantasy from reality and in the case of children it is the duty of the parents to regulate what their child watches and also to discuss and clarify any questions the child might have. The people that lash out and commit violent acts in society do so because they are extremely isolated or feel they have no other choice. Of course there is an extremely small percentage of people in society who enjoy the physical suffering of others and would even actually act on their desires. These are the type of people that become serial killers and they suffer from a social disease that was most likely brought on in childhood from some traumatic event in their life. They are mentally sick and need help in order to deal with themselves and the world in a productive way.
Censorship of gore in movies is not the answer to any problem in society. There will always be people who have a desire to watch gory media and there will always be those who oppose it. The market will dictate whether gore is successful in the media.
Gore is a part of life just like any other and it will be represented in movies. Sheltering ourselves from gore will not make us better people, it will just make us more ignorant of the uncomfortable realities of life. If you watched front line battle footage of the war in Iraq would you contemplate what was happening and why or would you simply dismiss it as "too gory"? It is important to represent gore in movies because it reminds us that these things do in fact exists in our lives whether we like it or not.
Watching extremely gory media is still less traumatic than actually experiencing gore in your own life. There is no film that can match the intensity of fighting in a war or being an ER surgeon. In the case of the surgeon, he or she must be desensitized to gore in order to perform a surgery that may save someones life. Because a doctor understands the human body they can easily overcome the shock of a gory situation and perform the necessary tasks to remedy it.
Sure there are movies that rely completely on gore and gross-out factor to draw an audience. If there is a market for these types of movies then someone is going to capitalize on that market whether you approve of it morally or not. This will always be the case in a free marketplace.
We as consumers of media have a choice in what we watch and no one can force you to watch any gory media that you do not want to. If you do not approve of gore in movies then you should stop supporting it with your money and your time.