There's also the fallacy that scientists will only make pure objective decisions but scientists are in the end only humans and have their own believes, failings and political agendas. The whole system of peer reviewing and the acknowledgement that every scientific theory can be falsified is a testament to this realization. Unfortunately I have the impression that in politics too often individual experts are only heard and thus the whole system of checks and balances in science is circumvented and particular scientific opinions might get more weight than justified.

Still, I believe that the scientific methodology (not necessarily individual scientists) is still our best hope to actually achieve improvements as shown by our rapidly expanding knowledge since it was more formally defined. It just has to be tempered with clear political goals.