If you think about the Enterprise being a heavy cruiser, a ship that needs lots of room for labs and troops and entertainment centers and to keep from feeling claustrophobic as you're away from home for possibly very long stretches, doesn't it follow that smaller ships and ships without as broad a mission envelope would either not have saucers, or, maybe, have primary hulls of different shapes? In a Federation of so many billions and of such construction capabilities, wouldn't it also be really easy for them to come up with new designs for ships rather than re-use quite so often kit-bashed designs? Voyager isn't cobbled together from Galaxy parts, even if it is in the same esthetic vein. When it's a hero ship, or as CG has made it easy to, they come up with more original designs. I always like it when ships either use different kinds of primary hulls, or none at all.
Towards the late 24th-Century, saucers were beginning to be phased out somewhat in lieu of different single-hulled designs. For all we know, the Sovereign-class may have been the last hurrah for them (we don't know exactly for sure if the alternate future Enterprise-J design will truly come to pass, but it looks like the Wells-class timeships could be indicative of where future starship designs may go with them being more and more organic in appearance).
Well, there's also the off-camera consideration that Federation ships need to be fairly easily recognizable to the audience as being a Federation ship. That's really why they tend to stick with the two pylon, saucer/secondary hull design aesthetic.
...my problem with the Wells is that it looked like it could be an alien ship from the 24th century. It has the basic T-shape of many (most?) alien species. Does this mean that the aggressive T-shape used for baddies is actually the more efficient design? Yeah I get that, but it doesn't sit well with me as a casual viewer too. The smaller the ship is the less graceful a saucer looks. How is it more? Starfleet are the only ones who use it, and I get the impression it's mostly because Hollywood executives think we're too dumb to identify a Starfleet ship w/o a saucer, or a Klingon ship that isn't a T. Heck, even their tankers look like the ST:III BoP.
Identifying the "Marauders" ship as a tanker seems to be missing the mark somewhat. The apparent purpose of the ship wasn't to refuel frontline assets or to haul fuel from A to B, but to pillage fuel from primitives. Essentially, it's what it looks like: a combat ship engaged in looting. A medieval knight's mount might look pretty much like that after a successful battle. In contrast, the Klingons have plenty of "purposely shaped" ships (although one always wonders which of those are of indigenous make, and which are loot themselves). They have the giant container ships that seem to sell well in the Cardassian circles, too; they have all sorts of oddly shaped "civilian" ships and scouts, they have the aggressively thrust-vectoring "coast guard" D-4s... If there's a culture that really overuses a shape, it's the Cardassians. I mean, yeah, the Romulans seem to have a limited range in any given era, too, but we only get to see two or three types per era anyway. But Cardassians go for the ankh/horseshoe crab shape for the big destroyers, the small patrol ships, the small freighters and even the work pods (and, if we want to open the DS9 Tech Manual, probes!). When we see differently shaped transports in Cardassian colors, they are always types or designs also operated by other cultures. Timo Saloniemi
Isn't this like saying Superman's outfit needs to drop the S? They're not gonna cut what makes a Star Trek ship instantly recognizable as a Star Trek ship.
Ithekro, tail wagging the dog. I'd rather a future timeship be a giant ball of light than have to be limited to more T's. ...at this rate, every ship, starbase, probe, and building in Star Trek will be a T by the final season of DSC. But I want to look at TOS Enterprise. The actual ship, the part that did everything, is the stardrive section. The engines, the power core, the sensor dish, the cargo holds, the shuttle bays. That's the ship. The saucer is this luxurious campus attached to it. If you didn't need labs or as large a crew, would the saucer really need to be there? No one else uses saucers and many don't use segmented hulls, so it's not warp field dynamics demanding the shape. (Also, there's no such thing as warp field dynamics.) The original Starfleet design isn't simply saucer and nacelles (the Franklin) or simply saucer (the Defiant), but this intriguing, vaguely anthropomorphic, array of parts, including a spacious saucer. The ship was interesting in part because it seemed to adhere to some internal logic that made sense. I think a lot of designers focus too much on the standout parts of the design (the UFO saucer and rocket nacelles) and ignore the sense of it. It's like designing a sailing ship but only drawing sails attached to cannons.
They're also diluting what makes certain Star Trek ships special. It's like sticking the S on Perry White and Lois Lane because people love the S and associate it with the Superman universe.
OTOH, Trek is a thorougly military show. So, uniforms. And indeedly, we're used to seeing every ship look the same ITRW. Back in the age of sail, the rigging may have differed, but beyond that, it was down to counting the smokestacks and turrets, a humble patrol boat essentially looking like a giant battleship washed in too hot an ocean. While diversity might be fine for starships, this if any is an excuse to go for dramatically useful uniformity. Timo Saloniemi
The Wells-class is simply a departure from the "traditional" Federation starship designs we've seen up to now, but that's really the point of it. Being a product of the 29th-Century, it just has a different aesthetic that could be fairly common among Federation ships of its era. No more so than the Y-shape used for heroes, which could also be viewed as aggressive (or weak) depending on your point of view.
I think the real question is why do TNG shuttlecraft look like minivans? I just watched the episode with the Shelliac last night, and boy did Data's ride look cheesy. [But it has that 90s charm]. DS9 definitely upgraded the "light craft" look with the runabouts.
There's also no such thing as Federation Starships, which is probably why it's ok that they are mostly built around saucers. Honestly, a saucer is a pretty advantageous design. It allows for good interior volume while having a relatively low profile from certain angles.
Saucers are actually quite efficient when it comes to starship design, making use of internal volume and it's faster to go from one part to another than for example long ship like Vor'Cha class cruisers or Vulcan ships.