The Klingons ended up a lot less simplified at the end of DS9 than at the beginning. By the end DS9 portrayed them as hypocrites and politicians who use honor to their advantage when it suits them and ignore it when nobody's watching.
DS9 era klingons believe in honor the same way republicans believe in family values. They talk about it a lot, they tell a lot of stories that cherish it, but only a handful of them actually practice it.
But there is still a problem - they are hypocritical and aggressive to the last man - not as single one of them behaves practically, naturally, rationally, or calmly - all hallmarks of sentience, that can't simply be explained away with genetic predispositions to aggression. It's as if the worst demagogues that you mentioned, were multiplied, and made up the entire of human society.
It begs the question: How did they ever start a civilization?
Thankfully, JJ Abrams applied the same natural standards to the Klingons in the short time we saw them, as he applied to the character of Sayid in Lost - an Iraqi Arab, Muslim, and former member of the Republican Guard (so maybe a Ba'athist sympathizer in the past) - yet not some one dimensional cardboard cutout who found it necessary to remind everyone he was a soldier, or Muslim, or Arab, every five minutes. That's natural writing - and that's natural human behavior.
I see these degenerate, reactionary, romanticist, racist, nationalist, bigoted, aggressive, moronic, technophobic, Luddite, philistine Klingons that we often got, as a poor sample of their population - hopefully, we will see from now on, that the majority of them behave more naturally.