It's like intelligent design, fill the gaps in our scientific (in this case historic) knowledge with "God" and then go to lunch, it is the laziest form of science and history, the only evidence for it is that it is very difficult to 100% dissprove something, because no matter how much evidence there is for something, if it isn't completly bollocks then a few thousand people will believe it, all with the benefit of having to do no research or study, why bother when "god/alien did it" fits fine