[fatbird]

I think you put your finger on it there: Klingon honour culture. In other words, there's an admirable culture underlying the exterior brutishness; a human in Klingon society had something to grab onto that they could respect and work with.

As I recall, the Ferengi never received the same thing. They were always their miserable, grubby little selves. Even Cardassians were given an underpinning of extreme loyalty to family and the security/success of their children, which explained their rigid society as an outgrowth of that strong internal family order. Some of the best scenes in all of Star Trek are where Garak explains Cardassian culture--like how their literature is always about how the state is right.