Aside from 40K, I don’t think it is unreasonable to have a warrior race centered on a culture of honor/pride to be into physical trappings manifesting such things. I think you’re conflating “warrior race” with something like a utilitarian race with a singular focus on efficient war-making.
God no. :) W40K’s fiction is way too far into fantasyland for me. I’m a science fiction guy. Totally see how you can embrace W40K without thinking it’s just ridiculously silly and unrealistic if you extrapolate a future that starts with a Tolkenian fantasy world. But I prefer fiction based on extrapolating from reality – which Star Trek is supposed to be.
If you look at the interior of Klingon ships, the uniforms they wore in the TNG-and-on era, etc. it’s been very much a utilitarian focus. The only flourishes seemed to be the architecture on Qo’noS, and perhaps the use of leather in their uniform designs is an homage to an earlier era, since leather probably doesn’t do much against a disruptor.
But the outfits we’ve seen so far look like they’d horribly hamper movement, and the ornate decoration is like nothing we’ve seen before. There’s no precedent for this level of arbitrary, unnecessary change. There was a huge change from TOS to TNG, but that was the realities of budget, technology, etc. changing in TV, and they even tried to explain that in the fiction of the show. From ST:TMP all the way through the end of Voyager/Enterprise/Nemesis, further changes to the Klingons were subtle.
At least when Voyager decided to re-imagine the Klingons as a species with that makes really horrible hair decisions, they had the decency to call them Kazon instead.
I’m still hoping there’s an explanation that these are time-displaced Klingons from a sillier time, and that the “current day” Klingons in the show will mesh more with precedent.