I may be mistaken, but I believe that the basis of the movie "Expelled: No Intelligence Allowed" is that the scientific community is not as objective as it should be on hot button issues. The Theory of Evolution is used as an example of how science has been transformed into a battlefield for a war between theists and atheists. Pride, politics, preconceptions, and political correctness have all turned the scientific community into a "hostile and subjective" environment for theories that go against mainstream thinking.
Even though this may be true to a certain extent, I believe that those that view science as attacking religion and vice versa are missing the larger point, "Truth goes beyond established facts." All our scientific knowledge is only a small piece of the complete "truth" of the universe, despite the fact that many scientists and atheists consider the scientific method the end all of epistemological methods. There are many other places where knowledge and truth can be found, such as in philosophy or the arts, and do I dare say it, the one true religion.
Finally, as far as ID goes, it fails as a scientific theory largely because people view it as another attempt by creationists to teach religion in our schools (as implied in the movie). It also fails as a scientific theory because it is not falsifiable, another curiosity of science that limits its ability to think outside the box and constrains it to truth in "observable reality" (which is only as good as the instruments we use). If it cannot be observed then it does not exist according to science and that is why science will never discover all truth.