> What is a "fact" or what is "true" in dependent on your values (aka your ideology). This is one of Nietzsche's main contributions to philosophy.
No, it's not. That's one of the Enlightenment’s many contributions to philosophy and the foundation on which the advances in knowledge of the universe enabling the explosion of post-Enlightenment technical progress is built.
Obviously, one might have ideological, aesthetic, or other preferences for what facts ought to be, and one might have beliefs about questions of fact that ultimately result from those preferences, but—Roadrunner cartoons not withstanding—beliefs about the material universe don't trump material facts.
(However, it's kind of funny that you are making, as a positive argument in favor of conservatism, exactly the argument that conservatives usually not only reject, but also attribute—not entirely inaccurately though certainly overgenerally—to the “postmodern” left and cite as a key reason for rejecting the left.)