alt Hacker NewsFrom my experience in research this was already the case 15 years ago (and from older peers, way before). Science has always has "in-groups". I forget the name of some philosopher in the 50's who was the opinion science is just a bunch of fads and it takes the old generation to die before a new idea can really be accepted.
“A new scientific truth does not triumph by convincing its opponents and making them see the light, but rather because its opponents eventually die, and a new generation grows up that is familiar with it.” Max Planck 1949
Commonly paraphrased to: The knowledge quest proceeds funeral by funeral.