Because you're wrong. Both the Carrier and the Destroyer are adapted civilian designs, not ships designed from the ground up during the campaign.
The Deacon was originally intended to be a new generation of heavy transports...
The Shaman class Carrier had been in development for some time before it was finally brought into battle. This Carrier was based on Kiith Somtaaw’s first foray into heavy ship construction, the Chieftan class Ore Processor...
In both cases, the designers did in fact have time to design properly, because they were both originally intended to be civilian industrial vessels. There's no reason they need to look as terrible as they do. The only one that was rushed like you describe is the dreadnought, and while it looks bad, it's still by far the best-looking Somtaaw capital. The Kushan Heavy Cruiser is also a really ugly ship, but Somtaaw ships make it look amazing by comparison.
I could address your point into nitpicky levels on differentiating how a civilian vessel design being adapted to military function could botch the entire sillouette of the ship, turning it into the ugly ships we all got in Cata, but that's also missing the point. The big point here is not whether if some writer in the development team found that they couldn't really explain how they got to design so many ships from scratch, so why not explain it away with some line about them being based on civilian design. It makes sense that they did so, but that's, again, missing the point.
The point is, and I've been saying this three times now so I will call it quits if it doesn't get through, that the main characters
of Cataclysm are miners
. They are NOT "beautiful" people. They are NOT the elite of the elite, BP Age of Aquarius 14th Battlefeet style, or even HW1 fleet style. They are miners. The janitors of the economy. Tolkien called them either trolls or dwarfs. They are the sweaty drunken big muscled people who would smack anyone in the face in the engineering room if someone started rambling on how the design was "ugly".
It can be the case that it was sheer lazyness. I'm not at all bothered by that, and you can refer to the "death of the author" in this case. I see not "lazy ships", but rather "Fugly ships", and that's what drives the characterization of the protagonists. To me, it was way more scandalous that the "moon base" was also ****ing ugly
(and other third party ships), because those were out of character
Not the miners. The miners are supposed
to be ugly. This attempt to Brad Pittyfy (or Angelinalize) every single thing on-screen is a thought cancer. No. Ship designs are not beauty contests, they are character builders
. This is why, incidentaly, the Millenium Falcon is such an incredible icon, despite someone saying "What a piece of junk!"
It is a piece of junk. I know, I know, it also has some good lines in it (the overall shape is sleek), but to the average viewer in the 70s, used to sleek designs in sci-fi, it appeared like a garbage truck with electronic trash glued in its outside.
So, even if I completely 100% agree that that Destroyer design is ugly as hell, I also think that's completely in-character
and paradoxically gives weight to the game.
And there's no excuse at all for the laziness of Somtaaw corvettes.
Note that there's a difference between "good-ugly" and "ugly-ugly". That concept up there is the former. Somtaaw capship are the latter. An in-universe justification is not needed for the former because the design says it all already. And if you need one to justify the latter, you're designing your ships wrong in the first place.
I think this difference of "good-ugly" and "ugly-ugly" is too thin and too subjective to discuss, but I could indulge such conversation. Again, as I also said, and no I am not wrong even by pointing this out, I don't mind that this "uglyness" has a bit more depth and interest in it. It totally can and probably should.