Yeah, that's interesting. I actually didn't think of the assassination attempt in Apocalypse Rising. I think its a revealing point in the character of Gowron. Because when Gowron and Worf face off and Gowron stops any of the nearby Klingons from interfering, his motives are no doubt mixed. Of course from a storytelling point of view that's how Odo figures out that Gowron isn't a changeling. But digging a little deeper, I think the question is what are Gowron's motives in fighting Worf and not letting one of the many other warriors there do it for him? Are they simply based on a desire for honor? Are they political in some way? Or is it just Gowron's dislike for Worf, or anyone who defies him really?
I think again, the answer is a little bit of all of the above. Politically there are reasons to want to fight Worf and defeat him in combat. Klingons value strength and the purity of combat, and so having Worf simply killed gives him nothing, but killing himself as he tries to assassinate him will increase his political clout. And Gowron obviously isn't afraid of a fight. Indeed I think it would be impossible for him to be in the position he is in and maintain it without some serious chops when it comes to personal combat. And we do see a lot of evidence of that.
In addition, its very possible that doing what Gowron did in the wake of the Cardassian Invasion, simply stripping those houses that disagreed with him of their lands, wealth and honor, wouldn't be looked on too favorably by the other houses. Its kind of an underhanded move, a political maneuver to quiet dissent. The other Houses may have looked at that and quietly wondered if a similar fate awaited them. That might seem desirable, until you realize how volatile Klingon Politics is. Taking down a House (or possibly Houses) that defied you through political means may be seen as a sign of weakness, a sign that Gowron is frightened of dissent and not strong enough to stand up to the House of Mogh like a Klingon. Fighting and killing a symbol of that move might go to healing that wound.
Secondly, I think there is a part of Gowron that really wants to just fight Worf and beat him because he's defied him. Gowron takes Worf's refusal to side with him in the Cardassian war perhaps too personally. But I think being in his position, and having that strong sense of self preservation, Gowron may err toward the paranoid. After all, neither Worf nor Martok were really all that interested in challenging him politically in the end, but he certainly felt they were. So once Gowron sniffs any sort of disloyalty he begins to look at that person as a potential enemy. In what could be considered a very tragic flaw, his paranoia actually creates the enemies he's paranoid of. That, psychologically, could be a result of him being an outsider. He had to fight for everything he got, nothing was handed to him because of his name, in contrast to people like Duras. He has a chip on his shoulder and he never forgets it, even when he's destroyed his enemies and sits at the top of the Empire.
And because of that, I think Gowron really wants to take Worf out. He wants the purity of one on one combat and the ability to stand above one more dead enemy to prove that he deserves the power he's fought so hard to achieve.
My real question I guess is how much does a culturally ingrained sense of Honor have to do with that as well? I don't know. I'm sure it's a factor. When I think about Gowron, my mind instantly goes to Worf to draw comparisons. Both are somewhat outsiders. Gowron an outsider to the higher levels of Klingon society, Worf an outsider to Klingon culture altogether. And because of that they both seem to overcompensate, but in entirely different ways.
