I know these outrageous alien theories pretty well -- they are a hobby of mine. My take is that they are a sort of science-like mythology that substitutes space aliens for the gods that we can no longer believe in in our modern technological age. The claim is not that "Mayans were so primitive that they couldn't have accomplished all they supposedly had done without alien help, but we white men did it all by ourselves," but that all of humanity is, in origin and in development, the work of aliens. We were created by aliens (sometimes the idea of "after their own image" pops up), and technological leaps and feats, especially in ancient times, were the result of alien intervention. But modern times are no exception -- some theorize that Einstein had alien help. What are we talking about here? Look closely: this is what we used to call divine inspiration in the Age of Religion.

This is just a brief paragraph on a rather complex matter, about which my thoughts have not settled. As for racism, certainly as an institution it influences our culture at every level, so I can imagine more subtle ways that conspiracy theorists may fall under its sway especially when theorizing about a people that has been largely understood through colonial eyes. I do think that some theorists invent tales precisely to knock down the imperialist narrative, though these tales might have been co-opted already. Attributing "wisdom" to the ancients (Mayan or not) that we moderns have lost, is something akin to the idea of the "noble savage," which is a way for empire justify its conquest while bemoaning a certain loss of innocence.