Were, and are, Blavatsky, Lovecraft, Sitchin, von Daniken, Bauval and Emmerich, responsible for actually inspiring such concepts - or were they, and are they, simply reacting to contemporary currents of thought and ideas?
That's the question that needs further critique, however, if answered in the affirmative where do we go from this point? If answered in the negative, many of the claims of those just mentioned are incompatible with one another. For instance, Blavatsky and Sitchin are not on the same page with regard to the supernatural.
I read Sitchin just after L. Ron Hubbard. Neither inspired me. I thought that von Daniken had a better story. But do supernatural beings require spaceships?
Blavatsky is closer to the subtleties of the supernatural ie it's an inward journey not an outward one. The problem here is that Lovecraft and Crowley et al have created a monster which most everyday folk steer away from.
Having said that, the report of Hans Glaser in Nuremburg in 1561 and also the writings of Charles Fort still pique my interest.