I honestly don't see what point you're trying to make here.
Nothing, just that sometimes it feels cheap to see aliens trying to seem alien by taking from real cultures while at the same time still trying to sound alien.
You realize that "alien" means anything unusual or foreign and not just stuff from outer space, right? By that definition, things from other cultures are alien.
Simantics... Just replace alien with inhuman.
So you're saying that people of other cultures are inhuman? Uh, no, that's not semantics. This is one of those cases where knowing what a word means is a good thing, because you're misrepresenting it. It's derived directly from 14th century French
alien, and previously from
alienus, meaning "foreign, strange, of another". The extraterrestrial connotation came about in the early 1900s.
In other words, "alien" is literally "other", something different from the speaker. To, say, a contemporary U.S. citizen, all of the following are alien to some degree: any city on the coast farther from their home, Poland, 13th century Burgundy, 27th century Earth, Bradbury's Mars, Coruscant, the Q Continuum, and the Borg.
All of that aside,
of course invented cultures share traits with our own! Do you realize how difficult it is to create and portray a culture which is entirely divorced from our own in a way that we can comprehend? The closest I can think of is Asimov's
The Gods Themselves, with the extrauniversal aliens divided into two types, "hard ones" and "soft ones", with the latter further divided into three sexes, "Rationals", "Emotionals", and "Parentals". Just about everything was as far as it could be from human culture and thought while remaining understandable, and even then it had to be couched in terms which we can interpret properly. We're human, and we write from what we know. The species of Star Trek are by and large humans with different racial worldviews, and so it is sensible that they have cultural elements similar to our own, just as it is sensible for the Horta, being so distinctly alien, to have little in common with humanity beyond the basic drive to have and protect offspring (going solely by TOS canon there).