Example (I'll let you be the judge of which one is being irrational): I know STEMers who are adamant atheists. I also know STEMers who are pretty devout and think that science supports all of their beliefs.
For a less controversial example just look at the sheer amount of fashion trends that sweep through the programming community. Pushing those trends is literally a core function of this website. Just like many people in america jump from fad diet to fad diet , and we jump from fad framework to fad framework. The number of software engineering decisions we make that are based on actual software engineering research is vanishingly small.
Fellow STEMers please understand that you (and me) are human and very likely just as irrational and emotional as any other group of people. Ignoring that fact will lead to a false sense of superiority.
Theoretically science is supposed to be that paragon of reasoning where we attempt to falsify our beliefs and thereby make the more correct ones stronger, but my interaction with the academic world has made me realize that science is again mostly about developing relationships so that your papers will be favorably reviewed, publishing junk to make sure your boss thinks you are productive, and researching whatever the people paying your bills are interested in researching.