On the question of whether UFOs do exist, and whether the ostensible sightings of them confirm the hypotheses that a) alien cultures do exist and b) they exercise their curiosity or will to communicate through paying us visits, I have the following thoughts to offer that (in my opinion) should be taken more seriously, yet they have not been put forward by anyone thus far:
For the sake of the argument, let’s accept that aliens do exist and that UFO’s are indeed their vehicles, sometimes hovering in the Earth’s atmosphere, with flashing lights etc.
Why do they not establish explicit contact? The reasons behind them not contacting us directly, or in any form that we would recognize, could be more fundamental than the hypothesis that “mutual communication signals do take place but we are talking past each other” would allow. This hypothesis of “talking past each other” is a mere speculation, a logical leap that projects to aliens [or to: Others] our own will and therefore somehow establish a proto-reciprocity in the very absence of any Evidence.
Two other reasons may also explain why “UFO’s present themselves but don’t communicate with us:
1) They are oblivious to our existence.
How can this be?
a) They lack the perceptual apparatus to allow them to perceive our existence;
b) Their perceptions’ Gestalt is focused on something else, on other forms of life, on other forms of psyches that they eagerly observe, or even they miss living organisms (as we understand them) altogether and can only perceive inanimate objects, or inanimate modes of energy. (One analogy of this would be: us humans observing with naked eye an object at the wavelength that the eye operates, missing altogether the life that appears at other wavelengths/frequencies. Another example would be: aliens don’t perceive us the way we do, for example as individual organisms, but rather perhaps they perceive the Earth as one single giant organism, just like the way we perceive a Giant Reef, a fungus super-organism etc).
2) They are indeed aware of our existence but they are totally uninterested.
How can this be?
a) They have come across similar civilizations in their past and have exhausted their curiosity on this subject and therefore don’t find us interesting subjects/organisms of study;
b) They find other organisms on Earth more interesting, such as microbes, bacteria, plants, other animals, or even perhaps non-animated organisms such as minerals, or other modes of beings such as gravitational forces etc.
c) They are not even curious about anything.
P.S. Lately, the cosmologist Stephen Hawkins warned us that an encounter with alien organisms would probably be dangerous. I say: it may be neither useful nor dangerous. None of the above. An accidental encounter of no particular interest. Barely an encounter.