I've often heard the argument against ET visitation that we must be so unworthy and uninteresting for an advanced species to both become aware of our existence and their wish to come here to study us.
I think this argument is flawed in a number of ways which I'll try to briefly outline:
For a start - thinking we are uninteresting/unworthy is an anthropomorphic way of thinking. We cannot begin to necessarily understand the motives of a non-human intelligence.
Also, I think we could be
infinitely interesting to another species. If we really are so very different than an ET species they may find our culture, our way of having wars etc an amazing opportunity to study an intelligent species whose morals and values etc totally different than their own. It maybe because of what we see as negative about ourselves that makes us worthy of study. Imagine an ET race is very automaton-like with little or no emotions; they may find our psychology utterly fascinating.
WE would no doubt find ANY other intelligent species in the universe fascinating. If we became aware of a nearby planet with an indigenous intelligent race, and we could actually reach their planet and study them without revealing ourselves to them initially, well I don't think you'd be short of takers to go on that mission! We would jump at the chance.
Even if another species is more technologically advanced than us, there may still be a lot of chemicals, naturally occuring alkaloids etc, or other technology that has not been discovered by them yet and they may welcome the chance to become aware of things not yet known to them.
Life might indeed be all throughout the universe, millions of inhabited planets and maybe even galactic type III civilisations. But even so, it might be the case that in our corner of the Milky Way, there may not be that many advanced species and we might simply be the nearest other inhabited world to some ET race so they might be reaching out into space bit by bit with us early on in their exploration.
Some people bring up the point 'how would another intelligent species even be aware of us' and that is a fair point. I would answer that already with our own radioastronomy we have discovered extra-solar planets that inhabit the 'Goldilocks Zone' where scientists think there is the possibility of life. A more advanced species may also be scanning the sky and looking for characteristic spectra of chemicals in the atmosphere that could only be the by-product of a living organism. There are ways, even at great distances, to increase our chances of identifying extra-solar inhabited planets. If we can do it, they can probably do it and probably do it better than us.
There could be things on this Earth of value to others that we are not even aware of. There could be something utterly unique and special about existence here of high value or interest to ET. If there for instance, is real truth to events at the Sherman Ranch or ghosts and other paranormal phenomena, then that might be unique to the Earth and very worthy of study. There have been many UFO reports in the Uintah Basin and perhaps some of those reports are of a kind of psychicly-created aircraft and others 'real' UFOs - maybe the 'real' UFOs are there investigating the high-strangeness too. Is it not possible that some ETs are from our own Galaxy and they could be just as interested in some inter-dimensional shenanigans as we/NIDS are?
Lastly, but not at all exhaustively, there may be natural resources in abundance here that are hard to come by in other planets. There have been many reports of USOs going in/out of oceans and lakes etc and there have been reports (and videos) of UFOs going into volcanoes and around other natural forces. Maybe UFOs are extracting heavy water (tritium) from the sea.
One former policeman turned UFO researcher in the UK, Tony Dodd, claimed he had found out there was official suspicion of a large undersea base near Iceland in the North Atlantic. The sea around Puerto Rico is known for heavy USO sightings too.
This has not been a complete list of arguments FOR ET coming here but I hope it may have given pause to someone of the opinion 'we are just not worthy of study' etc as I think that is a very narrow and human perspective and we just cannot assume to know the mind of an ET race. It would not be very ETish if we did!