I'm an evolutionary biologist. I can tell you that nothing-but-ism runs rampant among my colleagues. Much worse: fundamental physics. Plus all those physicists & neuroscientists who are computationalists. It's the majority view, far. Maybe not when you probe these folks about the complexities of their research practice in private. But 100% in their publications & 110% when they "popularize" their work for the public.
You must be moving in exclusive circles not to experience this...