I don't care so much about the prisoner thing...Trek can't hold it's Romulan Ale or it's continuity. That's a hard description of Worf's character but I can't say it's unwarranted but sometimes a sterotype is desirable and appropriate. Mostly though TNG was a group effort.
Yeah, I think Worf's problem is that he is kind of written as a stereotype, the noble savage all over again.
He is a symptom of a larger problem. In TOS the Klingons were dusky Soviets. They were cunning and brutal, but intelligent. Moreover, you got the impression that they were an example of a tyrannical culture. They were Genghis Khans and Commies in Space. They were like what we could be under a different form of government and different cultural inflections.
When you get to TNG and beyond, however, the Klingon becomes a caricature. They dress like the opening act for KISS or Motley Crue. They are increasingly brutal, but less intelligent too. They quickly devolved into a race of space pirates. What's worse is that their identity is no longer cultural but racial in TNG.
That is, it is in their blood to be violent and so on. Worf talks a lot about his racial identity and how he is different, despite the time he as spent among humans, as a biological entity.
Combine this with things like Q's heightened interest in humanity's superiority (and thus the threat they potentially pose) and his profound disinterest in the Klingon race, and you get the sense that humans are implicitly racially superior to the Klingons.
I think this is one of the most objectionable aspects of post TMP Trek (and this includes the aging TOS crew and their movies too).