Let’s just take Guardians of the Galaxy...
Star Lord’s mother made him mixed tape before she died. And his father, an arrogant planet, hired private investigators such as Yondu to find him. Yondu, his adoptive father, didn’t deliver Star Lord to his real dad, but he didn’t eat him either, so that’s something.
Gamora parent’s were killed but she was rescued and raised by Thanos, who cares so much, he is willing to sacrifice half of everything.
Rocket was created in a lab, so caring scientists acted as his surrogant parents raised him to be super intelligent.
Drax’s family was killed by Thanos, so Kronos put his spirit in a new powerful body.
Groot, a human tree hybrid, was also made by a scientist.
So inconclusion, they don’t have families because they were all either made in a lab or their families were killed, or as in the case of Star Lord’s dad, you just don’t want to know, because it leads to “Luke I am your father” moments.
I don’t remember that in the movies. Is that from the comic books?
All I recall about Groot is that his species was rare (comment from the Collector) suggesting his species was near extinct.
Checkout the pre-publication blurbs for the sci-fi book titled “The Bookeaters” if you want a strange family in fantasy/sci-fi
https://www.tor.com/2020/11/10/announcing-the-book-eaters-by-sunyi-dean/
“So inconclusion, they don’t have families because they were all either made in a lab or their families were killed, or as in the case of Star Lord’s dad, you just don’t want to know, because it leads to “Luke I am your father” moments.”
You’ve produced a brilliant post. Having written 14 novels, several of which are on Amazon.com, I can add a few thoughts. In science fiction you need to create a mood and an atmosphere that is appropriate to the genre. What is appropriate to “Little House on The Prairie” is not appropriate for “Star Lord Meets Xxcelax.” When you are writing, unless you’re doing it as a Russian author in the nineteenth century, you only mention things related to the story or to build character. Everybody I talked to loved Tom Clancy’s books. But at least in my sampling, they loved the story and skipped over the three pages on items like the total history of the Sikorsky CH-53E Super Stallion heavy-lift helicopter and why this particular one had skipped its planned maintenance and a critical bolt was about to fail. (I had worked on some of the equipment he regaled us with and even I skipped a few pages here and there.)
So, your main character either lost his beloved “Little House on the Prairie” family due to a Microsoft blue-screen-of-death software failure in their pleasure implants, or he was born in a lab and raised by a robot. (Take your pick.) People are reading science fiction because it IS different from “Little House on the Prairie.”
While I agree to a degree that science fiction downplays the traditional family, and many of the writers, on, say, the latest woke “Star Trek” are blue-haired family hating trans people, but it’s not entirely because they hate family. Even in the first “Star Trek,” if the family was mentioned or shown as a character building tool, the setting was austere with none of the scattered toys and spilled milk you’d expect in a normal house.
“Sometimes it’s just a cigar.” (Sigmund Freud)