There's a couple of serious problems with the Ancient Aliens idea. First it really still gives praise to the idea of a "linear history". This is a common pitfall of most scientists (of all types) and most people on the earth have fallen victim to this falsehood. Defined, it is the belief that man has evolved from apes and progressed through different transmutations to become what he is today. In other words, from primitive of old to modern of today. This is a lie. Adam was a real man and taught his children a complex language.
Another problem with the theory that I take serious issue, and one where I disagree with Velikovsky, is that God, first was not a big eyed, or any other kind of alien. He was and is real, and he is NOT supernatural. He may seem supernatural to us and our unperfected understanding. However, He has eons of learning and knowledge that makes Him appear to be supernatural to us. He does not need a wunderkind machine inside the ark of the covenant, He doesn't need a spaceship to travel. With our curiosity and untrained, unchained approach we risk becoming a heretic. When we proudly approach our creator and with hubris showing him what we are so proud of possessing, we insult someone who loves us and has given us great gifts. What He does is not supernatural, it is real and might even be said to be perfect science. We would be smart to carefully consider our ways before we espouse them as truths.
What I say does not exclude the possibility of other beings in our universe or beings that may regularly visit the earth. There is an explanation. More to come.