The Stig wrote:
But do you want to chance that part of the Narada and her crew survives the fall through the black hole to wreck havoc on some other part of the timeline?
That makes sense, of course, but he film does a piss-poor job of telling us why Kirk decides to flat-out murder Nero and his crew. It's a clear symptom of the writers strike and the filmmakers have mentioned more than once that they would have gone back to tweak that scene, if they could.
I always felt cheated when Kirk ordered all weapons to be fired on the Narada. Kirk actually wants to help, telling Spock that he figured this all out logically (Even though we never established that we weren't at peace with Romulus), yet Spock isn't down with that. And this is the actual end to Spock's development ark. He decides that he doesn't want to follow logic and instead chooses to murder Nero and his crew while they're defenseless and on the brink of destruction!
Kirk did not 'murder' Nero anymore than a policeman who fires a gun to stop a fleeing killer is a murderer.
Nero destroyed a planet.
He intended to destroy more.
He had the means to do it.
It would have been highly irresponsible
for Kirk and crew to let him have a fraction of a chance of surviving. The Enterprise and all her sister ships and their crews are the law put there to save the Federation from people like Nero.
If Nero survived and then escaped, Kirk would have been blamed and rightly so.
I wouldn't have even given Nero the chance of surrender. You can't take a risk like that.
And I know Kirk tried to save Kruge after he had ordered his son killed in TSFS but Kruge didn't have Genesis and Kruge didn't have a powerful ship that could take out 12 Federation starships and he wasn't yet near threatening to wipe out every Federation world.
The problem I had with the scene in question in ST09 was Spock's response to Kirk's offer to Nero. As emotionally compromised as Spock was, and staring the butcher of his mother and almost his entire race in the face, imagine how "Trek-like" it would've been if Spock had agreed with Kirk that something should be done to try to rescue Nero and his men. I'm sorry, I can't give Spock a pass on that no matter what he'd been through. Allowing what amounted to cold-blooded vengeance wasn't going to bring anyone back, and I doubt it made Spock feel any better. Indeed, I'd be bothered if it did. It was the sentiment of a thug, not a Starfleet officer. It was a low point for the character of Spock.
As far as STID goes, I didn't have a problem with what Uhura said. That wasn't the time nor place for long explanations. She also seemed genuinely shocked at Spock's cruelty and just wanted it to stop.
IMO Uhuru didn't believe people think Spock was 'cruel'. Did you see Khan break Marcus neck, break Carol's leg? That was cruel. Spock was trying to stop Khan from more killing and more havoc but Khan could have won without killing Marcus or hurting Carol.
Spock was trying to stop a murderer, an elitist who thought most people were beneath him and would not hesitate to kill in his effort to control and wreak vengeance.
Spock was fighting for his life. Phasers on stun had no effect on Khan. Was he supposed to maybe let Khan get the upper hand and escape?