Searching for ET - a flawed perspective

Within some astronomy circles there is a view that searching for extraterrestrial life in the universe is a good and worthy goal, both from a scientific point of view and the resources needed to carry out such research. Hollywood films such as 'ET', 'Close Encounters of the Third Kind' and 'The Day the Earth Stood Still' paint a picture of higher intelligence being understanding and interaction with people on this planet being one of positivism or curiousity. But on what basis would an assumption along these lines bear any resemblance to reality? The recent release of a muddled mess of a film called 'Skyline' presents a different view of aliens. In this film they are portrayed as overtly hostile and their arrival on earth is aggressive with humans seen as resources to be harvested. In 'Skyline', the human race is not successful  at beating off the invaders and succumbs to the more powerful alien force. It should not presumed that any life form outside of this planet would subscribe to the same values, beliefs or behaviour often recognisable to homo sapiens. The Universe in fact is a highly hostile and volatile environment and should any intelligence be found which has the capacity to reach this planet, it is unlikely to have benign behaviour or adherence to ethical and moral values.