Credibility of Ancient Astronauts Hypothesis

When one talk about ancient civilization, he must know about their gods that were associated with that civilization. These gods were often described as owner of supernatural power and mystical flying crafts having extraordinary ability even not achieved by our cutting edge technology. Many civilizations have depicted that these gods were who seeded knowledge of civilization and culture and came from heaven.
Von Daniken has termed these gods as ancient astronauts who allegedly came to Earth and seeded knowledge of culture and science including astronomy. He proclaimed that these ancient astronauts were actually came here to perform biogenetic experiments for their secret purposes. They were friendly aliens that helped human. This seems a likewise possibility with probability. However, how plausible it is? I don’t think that this one could be explanation for so called gods? Why one bother to come here on planet Earth for some genetic experiment that were even performed on their own planet or nearby planets? It doesn’t seems reasonable that an alien would come here only for genetic experiments that were even done on their planet by creating appropriate environment and it was easy too rather travelling many light years to such planet like Earth. It is more probable for me to consider that life on this planet has evolved many times instead of once and these gods were survivors of catastrophies that occured here and evolved supernatural intelligence and seeded culture again.