This just occurred to me, while thinking about Cronos.
This applies to all species that we see, usually, but Klingons provide a really clear example. If we can extrapolate from our own societies, the folks who join (and eventually run) a society’s military represent an extremely small subset of their culture. Someone who dedicates their life to sculpture, for example, tends to possess a very different worldview from someone who dedicates their life to launching ballistic missiles.
If this applies to alien cultures as well, we’re getting an extremely narrow view of each of these species that various Star Fleet crews encounter.
There must be, for example, some kind of pacifist movement in Klingon society. We know they love opera - I wonder if their society’s artists tend to be as anti-war as our own. And more to the point, I wonder what it’s like at a Klingon supermarket. Haha. Can you refuse to pay for something and kill the cash register person and just walk out with your groceries?