Aliens made the show
One of them has taken the form of Giorgio A. Tsoukalos's hair and controls him like a puppet. The show is meant to sound ridiculous so we can never take any story about aliens seriously. They're lulling us into a false sense of security for their eventual invasion.- Using the same logic they used to speculate that Leonardo da Vinci was an alien, how come Giorgio A. Tsoukalos seems to know so much about aliens, hm? How could he know so much about extra-terrestrials if he wasn't at least visited by one himself? Plus just look at him, he's got to be from another world. Is it possible? Yes, it is.
- Look at his hair. He's obviously a Centauri!
The show is secretly sponsored by The Men in Black
Giorgio A. Tsoukalos is either a MIB agent, or an alien they hired to spread information that is slightly true in an attempt to purposely make people think the idea is ridiculous. This show is in the same canon as Doctor Who.
The Silence has been influencing humanity through pyschic suggestion since the caveman days. Giorgio Tsoukalos has crazy hair because he's encountered so many Silence that it is now premanently standing up due to subconscious fear. Ancient Aliens is propaganda for the Church of Happyology
It's just so ridiculous that nobody believes it. The show is a Stealth Parody of people who believe aliens are real.
You're not supposed to take it seriously because it was made to be a comedy. That's why the production crew doesn't bother to perform legitimate research.