You also see it all the time.
"Well, you can't prove that god/angels/faeries/the soul/reptilian aliens aren't real, can you?"
"Well, no, you can't. That's how you know they don't exist, after all."
"So they are not real. Simply because I say so and am incapable of proving or disproving it - or rather I'm too lazy to try to prove them."
On what basis they are not real? On what basis can't they be proven real? They can be, only it seems to not be possible with our current technology and perception.
You can prove them, only it'd require
1) massive amount of real coverage of every single fragment of the Earth, including cameras or other devices covering the skies at the same time
2) actual close research and archiving (taping, recording in any format) of most of the universe
It's like I'd say "open-sketchbook never existed, I never saw him, somebody else must write instead of him, photos provided by him may be fabricated or they may be somebody else's, I never will try to meet him in person either (just because I assume he doesn't exist and I'm too lazy to do that)".
Never ever going to try to do that and that's why it can't be proven, eh?
Just like with OOBE's - if you never tried a real out of body experience along with scanning building insides and areas you never saw during physical travels or on photos, then you never tried to find out whether ESP is possible - and therefore - you can't speak whether it's factually possible or not, only ascertain probability of that. You can still prove it, therefore it can be true or false. You still can have an OOBE or do other experiments in a reliable way, LOL.
Attributing creation of world to God or gods (forgot polytheist religions, mind you!) or force (e.g. Tao in Taoism) are common examples of how humans tried to grasp and understand the reality around them without trying to actually research and crash test them.
Many of human beliefs concerning the reality (creationism) were seemingly proven wrong, incomplete or only partially right.
"- God is your conscious, and provides you with the soul that defines your individuality! Dualism has been disproven by study of brain architecture? Oh dear..."
No, the science doesn't provide you with knowledge, and the knowledge doesn't provide you with information. The problem are definitions of "science", "knowledge" and "information" in this comparison. And there's also a question of why the brain is capable of processing abstract ideas that are ungraspable empirically.
Also, concerning reptilians aliens:
1) ever heard about dinosaurs?
2) human culture records more than just one example of deifying reptilians as gods, for example, Aztec and Chinese mythologies feature them, along with the Bible refering to a snake as a walking and talking tempter (Genesis chapter)
So what's the probability of alien reptilians, taking existence of dinosaurs into consideration? Little up?
"And back in the day, it's either gods, forces of nature, or monotheistic "God" was supposed to control everything."
There are many definitions of god - when you speak about god/gods/God, then you need to clarify what supposed creationist forces you're talking about - they may be as well human hands creating man-made tools, and the "creator" of the tool can be called a "god" of that tool.
Isn't it true that human collective awareness that may be as well called God, experiencing and learning about political, religious, scientific nuances is shaping itself? So may awareness be a creator of itself?
So isn't your reasoning capabilities gods of your own reason, and still actively shaping your own reason, because without them, you won't be reasonable at all?
Also, there's a study called psychology. Why should be it suddenly ignored when dealing with abstract ideas such as conscience or personality? Goalposts were already moved by scientists turning to purely physical phenomena, they redefined "soul" and "conscience" and other inconvenient things as things of the past and nonexistent, while ancients simply may have imagine "ignorance" as "darkness", conceptualise their fears into "devils" and mythical beasts, and deified human beings that they considered worthy of following into gods (apotheosis). Various former terms, psychological research into such concepts is still less or more valid when dealing with human behaviour despite fans of purely empirical evidence for abstract things as "personality".