One of the problems is that science has become politicized. Industries hire hacks (including scientists) to attack any science that does not meet their needs. Think of the Chamber of Commerce's recent call for economists to write a paper that will attack health care.
Under constant attack, scientists may feel the need to "play defense." Just like a football team that keeps its practices secret to prevent opponents from learning their plans, scientists may well become insular.
In this way, industry destroys good science, which should depend on sharing of information.