As I said, no one disputes that people are seeing SOMETHING. What is disputed is what they are. Probably a combination of things. Still, does it make sense that we only see them here, and not in space on approach? We've got instruments to detect some pretty small objects out there. But if we want to fantasize, then I say they are historians from the future. That solves many problems like lack of alien remains and technology.
I have as much evidence for my wild guess as you do yours. None.
Why do you assume I haven't looked in to this. In fact, I've read a lot of books that agree with you. Unfortunately Von Daniken's et al methodology has been shown to be decidedly unscientific. Science begins with fact, according to the Scientific Method. Since you have none, I think it's rather silly to attack scientists by saying that they won't look in to it.
There's nothing to look in to.