Oh, this one is pretty easy, and the answer really has two main parts: just because someone knows a lot about geochemistry doesn't mean they know jack about archaeology, and don't read geopolitics rags for information on archaeology.

The roots of this go back to the early period of archaeology when the dominant mode of explaining cultural change was diffusion from a cultural center. So, for example, when European archaeologists started examining prehistoric monuments, they came to the conclusion that the period of vigorous monumental construction was inspired by the monumental construction in the "civilized" eastern Mediterranean: essentially, the Pyramids led to Stonehenge. This matched much older ideas of "ex orientia lux" (light from the east) which basically argued that civilization began in the east, and spread to the west. Egypt was known to be a very old culture even in ancient times, and so this generally meant that all culture was said to come from Egypt. This got taken to really absurd levels with "hyper diffusionism" which did silly things like posit that Egyptians sailing cross the ocean founded the Maya cities. Perhaps the most famous proponent of hyper diffusionism today is notorious crackpot Thor Heyerdahl.

Radiocarbon dating definitively put an end to this framework, as it proved that many of the European monuments were actually older than the Egyptian ones they were supposedly based on. Crackpots and charlatans are not known for their attention to the niceties of evidence, and so they continue peddling their discredited nonsense. One might say the same for science journalists.