You ask (rhetorically):
Put two books side by side on a bookshelf about the building of the Pyramid, one with the title "Alien Architecture: The true builders of the Pyramid" and "Khufu the Architect: Builder of The Great Pyramid" Which one would Joe public pick up to read??
It's not all that clear. The public appetite is fickle. In the US, the Tut's tomb museum show of real Egyptian artifacts was like a Beatle's tour. On the other hand, science fiction has always outsold Newtonian Mechanics--probably even to physicists.
Graham Hancock has done a great job of balancing these two sides in "Fingerprints . . . ."