King Daniel Into Darkness wrote:
"I've never trusted Klingons, and I never will. I've never been able to forgive them for the death of my boy."
He's definitely speaking of the people, not the political body.
Yes, he definitely (very understandably) does not like Klingons. That doesn't mean he wants them to die. It also doesn't mean it's impossible for him to be friendly to a specific individual klingon who has proven himself trustworthy, or even to simply suppress any latent antipathy he is feeling for the sake of completing his mission as smoothly as possible.
Now re-watch V, where he smiles and salutes the Klingon captain, where Scotty and everyone are having a great time totally at odds with VI's "guess who's coming to dinner"
The STVI dinner scene is very clearly not just about the fact that they're Klingons. It's about the fact that they're Klingons on their way to Earth to negotiate a permanent cease fire which Kirk believes is an idiotic idea which could destroy the Federation, and the fact that he's been ordered to roll out the red carpet for them despite his major objections, partially because Spock 'volunteered' him for the job.
If they were there to negotiate a trading agreement or something mundane, Kirk would've easily kept any residual resentment in check, because it just wouldn't be relevant to the mission at hand.
To get back to the actual topic, I think your definition of 'ignoring' sequals is rather broad. Just because a plot line is dropped or added here and there without explicit explanations doesn't mean TMP and WOK or TFF and TUC don't all happen in the same continuity. Contrast that to, for instance, Superman Returns which factually writes over everything that happened after Superman I by saying Kal el went to find his home planet and didn't come back until years later.