One can rationalize it, but the point is that aliens can't be anything but human beings with exaggerated/de-emphasized characteristics. Apologies to Willie Wonka, but "pure imagination" doesn't exist - writers draw on experience to create characters; everything that exists in fiction is ultimately a recombination of what exists, some of it more novel than others.
I remember people talking when I was young about how awesome Larry Niven's aliens were - so I start reading him, and what he invariably does is select one or two human behavioral traits and carry them to one possible logical conclusion. Everything about Puppeteers grows from cowardice, for example. Protectors are aggressively parental and...well, protective (the Niven formula is really something like selecting a single trait and then motivating the character by a presumed-to-be-universal desire to control everything).
Precisely so. Even Tolkien, with his wonderful world building, still recognized that ultimately, his stories were about humans and how they respond to things. I can't recall the exact quote, but the essence of it was that his stories would eventually become about humans because that his how the reader identifies with the story and characters.
Even aliens will eventually have a trait that makes them more like us. Even Mr. Spock (who was even more logical and alien at first) is used commonly to illustrate one of Freud's concepts of personality (Freudian Trio, as the trope goes, apparently). If aliens are made more alien, then often times there is either a character who ascribes human motivation to it (bonus points if they are completely right) or they reveal something that we humans can identify with.
This is meant as no offensive to anyone, but Star Trek has shown some fairly alien life, only for it to have human characteristics (The Horta, for example).
I guess my point is that it isn't a bad thing. YMMV, I guess![]()
We are actually surrounded by "alien" beings. Animals. In real life, we often anthropomorphize them, sometimes with tragic results. In literature, we use them to explain the human condition through parables and other forms of story telling. In reality, short of mind-melding with a tiger, we really can't know what life force is in them without explaining it from a human point of view. We have no common frame of reference with an eagle about how it thinks and how it sees itself in the world.
Within the story in TVH, Spock's mind meld with Gracie only served to make the whales seem more like us and turn them into sympathetic characters with a personal point of view and rights that had to be respected. Their "human" traits served the story just like any alien's in Trek.
I think the closest Trek ever came to a truly alien culture not understandable or explainable through any human traits or motivations were the Borg. And that didn't last long before human traits were seen in some of them.