Thinking a bit about TNG, and how the sense of wonder totally vanished from the show as it progressed, i keep wondering if focusing on some of the species like the Klingons, the Borg and the Cardassians and giving away so much information about them during TNG's later years and in DS9 was the wrong decission.
I can understand and like this fact for DS9 but for TNG, it may have been better if the producers hadn't done this so much.
To answer the question: Yes. Most sci-fi knew of tome constraints and kept planets as having one civilization in one area, as opposed toi many differing ones - which would be far more likely.
Also, as more and more gets fleshed out, the risk of losing context and tripping over continuity CAN be an issue. Not always, especially for smaller things or things that the writers and/or audience forgets, or if a new trait is added and there's usually a good reason to do so to expand narrative and universe-building. To tell the audience one day that a human has two lungs is fine. Five stories or twenty five stories later and all of a sudden, said human now has three of them... it's as silly as setting up a narrative where humans have lungs and need to breathe oxygen and remind us of that in a story, but then near the story's end forget to remember that either for characters or life support systems showing that life support systems dispensing oxygen are turned on. The bigger the emphasis makes for a bigger narrative stumble. Do note that as the decades have gone by, audiences have become more sophisticated in this sort of continuity as it builds a deeper and more substantial narrative. Also note that we're not humans but are Arcturans watching a show that features a race called "humans".
After a point, the snowball crafted is so huge that some parts of continuity will simply not be remembered. It's a good reason to not start showing a franchise to a person in season six of its second or third spinoff then hightail it back to season one of the first show that spawned a million sequels...
...and at some point it's best to ditch the continuity and make a new show set in the future, with - if any - loose tie-ins and let the audience piece the narrative together. That's why some loathe prequels, of which many screw up answering questions while making a bunch more, of which are often so horrendously bad and/or basic...
But some people lived "Caprica" and "Enterprise" too. Each person in the audience has their own expectations and desires as a series goes on and on.
Even TWOK isn't the same feel as TOS and its makers sat through all 79 episodes to find both a narrative expansion AND a balance, as what worked in 1966 would not fly in 1982. Fast forward to, what, 680 episodes instead of 79 just for the sake of a prequel and/or sequel set in the same time period as the progenitor show? Erm, no, that's not going to happen either which way... never mind other influences such as societal mores and fads and target demographics and how those demographics might react compared to the same demographics of decades ago acting. (e.g. TOS was never aimed at kids but some kids liked it... or better yet, Star Wars - a cartoon like Jar Jar Binks was not needed in 1977. The most the original trilogy got was a burping frog in ROTJ (aka ANH-LRv1*). That Nickelodeon crap wasn't needed or wanted but younger demographics weren't looking for bodily function jokes as comic relief as such back then, which is not entirely the same situation today**...
* A New Hope - Loosely/Lame Remake version 1**
** but I digress...