What's to explain? The FF is all about family.
Maybe
now. "The FF is all about family" is certainly what people tend to think about the FF
today, but I would argue that that aspect of the FF has been over-emphasized and blown way out of proportion compared to the original concept.
Are they about family? Sure, I suppose it's a fair classification if not exactly, technically accurate. Are they
all about family? I don't think so. At least, not originally, and the FF as a franchise would probably be more entertaining and more successful if filmmakers would back off from that angle a little bit.
Again, consider that the group we're talking about consists of a guy, his girlfriend, his buddy, and his girlfriend's brother. How many groups of people like that have you known that consider themselves a family? I used to live with my girlfriend and her brother. Sometimes a good friend would come over. I don't think "family" would be the most accurate word to describe all of us. It's
close, just not the
best word.
I doubt that when the FF was being conceived, they were conceived as a "super hero
family". Rather, it looks like Stan was just trying to come up with a realistic situation for these 4 people to know each other, as opposed to a bunch of super-heroes banding together just because, like the Justice League, or the Avengers.
Then look at the stories. Look at the Lee/Kirby run. Yes, there's some fun stuff in those stories that deal with how the FF does and does not get along. Yes, there's a family element to the FF, and yes, it's important. But it's not at all accurate to say the original Lee/Kirby run was
all about family. It was about
other things just as much, if not more.
The FF was the
first "Marvel" title, and Stan has said over and over again that Marvel's big breakthrough was crafting stories about superheroes with realistic problems and personalities, as opposes to 1-dimensional, perfect, problem-less characters. The FF had to pay their rent, Ben was miserable looking like a monster...the FF was the first superho-hero comic to inject some measure of realistically mundane problems into the superhero mileu.
That's what Marve & the FF were all about. Is that the same thing as being "all about family"? Not really. Now, when the comic is about a team, those things are closely related, but they're not really the same thing.
Also, the FF was about exploration, and taking the reader to weird, exciting places. Compare the FF, with say, Batman or Spider-Man. Pick up a random issue of Batman - he's probably in Gotham City. Spider-Man's probably in New York. Pick up a random issue of the FF, and they're just as like to be in some bizarre, extraordinary, exotic place as they are to be in New York.
When you read the original Lee/Kirby run, there's little to indicate that the core-concept of the FF is the theme of a "super-family". Again, it's an
element, but by no means the
main element.
I don't know exactly how or why this notion that the FF is "all about family" took root, but at some point it did. Probably the same mechanism by which Wolverine's super-healing was scaled up to the point of ridiculosity. For some reason, writers latched on to one particular thing about a character(s), became fixated on that one thing, and blew it way out of proportion.
Anyway...regardless whether you agree or disagree with my points, they already made a couple FF movies based on the "FF as a family" premise, and those movies weren't very good. Maybe if they'd back off from that angle, and emphasize some other aspect of the FF, we'd get a better, more exciting, adventuresome story.