I'm going to fansperg for a bit about Klingons, okay?
I was just watching SFDebris' episode on House of Quark, and I think I finally figured out how to reconcile Klingon culture existing with, well, Klingons actually existing. At least, original Trek klingons, from the TOS movies through Voyager.
I'm sure I'm not the first person to think along these lines. I think there's even been a few allusions to it in the various series... The klingon geneticist in Enterprise, for example. But basically...
We're not seeing Klingon culture. Not really. Klingons are basically a hereditary aristocracy, with great houses and warrior-generals and stuff. Even poor orphan Worf was technically born into a noble house. The average klingon, the merchants, the scientists, the engineers, the... I dunno, janitors and prostitutes and whatever. They just don't enter in to the world we see. Probably very few of them leave the homeworld. They're a semi-oppressed undercast that the aristocratic warrior caste have little use for except as Batleth-fodder when they go to war. When we do see them, they pay as much lip service to the klingon ways as they have to to get by, but they're not insane. The klingon aristocracy may scoff at finances and science and stuff, but someone has to do it.
Now, this isn't a perfect society even if we allow for this. Because the warrior-aristocracy, the.... The space-shoganate, let's say, are influential enough that they do direct how society evolves. For example, we know klingon medicine is considered primative by federation standards, because they have a more blase attitude towards death in general. Honorable deaths should not be circumvented by putting people back together, basically. But it lets their society function, mostly. The bumpy-headed samurai look down on the peasants and try not to think about them, but they're still there, keeping society going.
... Sorry. Random, and hell, it's probably been dealt with in a novel or something.