Nothing can rule out aliens if one does not want to see them ruled out.
Writing exists in practically all "tribes" that have transcended the Stone Age (those that still live like in the Stone Age don't usually have a
writing system), in a great variety of forms (alphabetic, syllabic, hieroglyphic and so on). Who gave it to us? And, more importantly, WHY? If we are
capable of developing a system of writing to organize and preserve thoughts, traditions, religion and history why do we need aliens to move stone
blocks for us? Because it is "trendy"? Because it makes us, briefly, the center of attention at parties or gatherings?
I do have two great problems with aliens, ancient or otherwise. While I cannot deny the possibility of alien life (in fact, it is highly possible that
life exists in very many a places in this universe, intelligent life may be sparser but still one cannot deny that this possibility is also very
high), I cannot see alien intelligence residing somewhere near us. (at times, it is hard to see intelligence on Earth also but that's another
-One, the vast distances would make repeat trips impossible during one's lifetime (while we may want to take what many fringe "scientists" say at
face value, the laws of physics still apply), since those aliens are "described" as being more or less humanoid in form they would originate on a
rocky planet with conditions similar to those on Earth, no? After all, it is "said" that they survived on Earth (how could they not, since they
taught Earthlings all those goodies?). While rocky planets tend to be smaller and thus more difficult to see, with current technology we should be
able to spot Earth size objects within 10-12 light years, provided they are close to a star. No such thing has been spotted so far so IF they do exist
somewhere near they are "hiding" - if they do exist further away they must have different physics unless the laws of physics that we observe are a
product of some obscure "establishment" despite the rigorous tests (General relativity, for one, has been subjected to thousands of tests in the
past 96 years, all those test had "doctored" results?). To put it simply, if they live close enough for repeat visits, where is their base? If they
live further away, how did they survive (or even attempt?) the journey?
-Two, and this one is bigger. Is the average human being so unbelievably STUPID as to not be able to understand certain basic facts about its
surroundings? For example, that certain plants are edible, they produce fruit (or spores) that can be planted and wield better harvests? That the
seasons on Earth follow a repetitive pattern? That if you manage to "roll" a large stone you can move it without having to LIFT it? That some
substances are harder than others, or more "elastic" or more manageable according to one's needs? For example, granite rock is among the hardest
stones around, in significant quantities. Nobody in the long history of mankind had observed that granite "chips" can cut other, softer, stones? You
need aliens for that? Or that water travels freely from higher elevation towards lower ones? (the basic starting point of irrigation) So, each and
every enlightened mind in the history of mankind was an alien? Aristotle, Plato, Archimedes, Eratosthenes, Aristarch, Copernicus, Da Vinci, Galileo,
Newton (the list is VERY long) and countless others that preceded these and whose names will probably never be known (like the inventor(s) of the bow,
for example, or the wheel).
In the end, the question is this one; why so little faith in mankind? Are we not capable of all those feats of engineering/endurance/ingenuity that
adorn our lands and are aged in the millennia and we so desperately need aliens?? Just because something seems impossible, by today's reckoning,
because the need for us to do it has faded so the "know how" is lost to us, doesn't mean it was always impossible.
I guess those who REALLY believe in ancient aliens actually HAVE to believe in ancient aliens (they probably judge the ancient man according to their
own example), if only they declared their absolute faith beforehand so they are judged too harshly!