Well from an author standpoint you do need some solid tech/sci knowledge to do it, most of the ones who have it do such things but ratchet it back so it doesn't become a dissertation and because a solar system composed of a few trillions little worlds is a bit intimidating to try to write a universe-shaking plot in, even though habitats make the notorious single-climate, single-city alien worlds a lot easier to justify. From a TV standpoint its just a pain in the ass, even these days, to film alien landscapes, e.g. every alien world in Stargate looks like a Canadian Forest, because they film there. On a sphere the other side of the world has a few thousand miles of rock in the way, on a spin-gravity habitat it's hanging overhead and the night time star constellations are other town's streetlights.

Not that you can't fake a normal horizon and sky on a big enough cylinder, it can have a 'ceiling' mimicking Earth's sky and you don't have to have a flat cylinder in favor of one where it bumps up and slopes down like a series of hills and valleys, and you don't have to go cylinders either, normal gravity on a sphere just needs to maintain a linear mass to surface area ratio so you could build a totally fake Earth 400 hundred miles in radius instead of 4000 and just fill the interior with pressurized hydrogen, gravity and giant fuel tank all in one. It's just the density of the filler material needs to increase inverse to the planetary radius. Saturn's perfect, you could englobe the thing and have a planet a hundred times bigger than Earth with Earth gravity and still be able to spin it to a 24-hour day, though you might want to make it wider at the poles to help neutralize centrifugal forces, alternatively if you wanted a planet 40 miles in Radius with natural gravity you'd need something 100 times denser then Earth to do the trick. Which is a bit tricky without using a black hole or something. On the other hand, deuterium is currently the ideal fusion fuel and ultra-dense deuterium is a matter state around 100,000 times denser then water IIRC so you could use something like that, basically living on a balloon ten miles across around your fuel tank with a couple dozen feet of dirt thrown on top, your own literal micro-planet as sphere... but I'm rambling, sorry this is one of my hobbies, there are wads of posts around here over the years where I wander off on this subject

Back to the original, yeah I think the general sci-fi plot revolving around little colonies of a few thousand/million work a lot better if the 'planet' is some habitat a million miles from anyone else and only the size of a smallish country. It also justifies the repeat use of scenery and filming location, if some company mass produced the "Montana Hab, perfect for 10,000 settlers interested in cabin in the woods life. It's just like Montana, before we erected thousands of mile high skycrapers there!" There's a lot of fiction options though, you could dump a few thousand in a clump somewhere and have little feudal realms with the aristocrats being the original main shareholders, dukes and barons and so on based on the size of their habitat, etc. I'd love to see more writers tackle such things.