I've never claimed that Varian didn't care about what happened to Bolvar. The opposite really, that Bolvar's death was the impetus to get him to do what he wanted to do anyway but had restrained himself from, as he states outright in the text. I didn't claim it's entirely about orcs but that it's primarily about orcs and that the text bears it out - the focus and emotional weight Varian puts against Thrall and the orcs is well beyond what Varian does Sylvanas and the undead. Which makes sense when you take into account he doesn't consider them a political actor and was already attacking them prior. Varian needed that shove to act against the orcs, despite all his grievances with them. He needed no such push when it came to the Forsaken.
To remove his grievances with Thrall and orcs from his call for war when he goes on about green-skinned abominations, given his background both in Orgrimmar and in the first sacking of Stormwind by the Horde to focus on the Forsaken is completely missing the gist of the character. There's a reason Varian and Sylvanas still team up later but Varian is never anything but cold towards Thrall even when they're on the same side - his grievance with one is political, his grievance with another is personal.