Sure, there are plenty of pseudo scientists out there that promote their political or economic agendas, but you can't discredit all science because of that.
Right now "hard" science is the best way to explain things around us and the universe. Sure, often it is wrong as new science gets discovered, but that's how human knowledge evolves.
As for the "soft" sciences (anything social/psyc, etc), that's a completely different matter. They are more prone to trends, fads and more personal biases, hence I would put them in a different category.