People want to believe shite. It's ni different than conspiracy theories like QAnon. It makes them feel smart and special without challenging their intellect at all.

The specific reason that they single out "mainstream" academia is that if you actually research the archeology, you see how Hancock's claims are ridiculous. The "mainstream narrative" is actually based on thousand of pieces of independent evidence, hard science.

I'm not dogmatic about it. For example the Younger Dryas Impact Hypothesis is perfectly debatable and has some evidence for it that merits further study. But Hancock is selling a fantasy story as if it's science, and he knows it's bullshit.