The shinobi world is incredibly different to our own, I wouldn't trust the leaf village to hold an unbiased court session. With most of the village semi-brainwashed by the events that have happened and someone like the elders or Danzo always being in charge behind the scenes I don't see this happening.
I think one of the core issues in the story is precisely that. The villages are run as a military organization, funded by corrupt and gullible feudal lords, with no checks and balances. The police force was created as a way to appease and distance a potential rival. Everything is done in secret. Yes, it's a different world, with magic and super powerful individuals, but they all still have the same moral failings. The solution that Shikamaru and Gaara are offering may be a short term fix for the current crisis, but neither is capable of seeing (or perhaps neither is aware of) the greater picture and the context in which this happens. So long as they don't change the system, it's just a matter of time until the next crisis arises. For all Gaara and Shikamaru are a lot more intelligent than Naruto, he is the one with the best insight on the right path.
Not to mention Sasuke entirely takes the law into his own hands. Shikamaru and Gaara were looking at the bigger picture that materialistically- Sasuke's death would've brought the Shinobi nations positive effects. It doesn't matter anyway as Naruto's resolve is the resolve we're morally following in this manga anyway.
No, it would only provide a reprieve for a while until the next crisis. Without reforming the system of hate and injustice, they are going to run into this again. Had Sasuke been given the facts and counceling, and the time to mourn, and help finding meaning, when he was still innocent and willing to listen, he may never have turned to the path of revenge.
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Does this REALLY look like the face of a guy who can be reasoned with? He went there with intentions to kill only Danzo but on the way managed to assault the world leaders, kill a bunch of Samurai because he was slightly angry and then lunge for both Karin & Sakura and fight with Naruto & Kakashi. You really think he wasn't prepared to murder any of these people? He fought/shot down all of them with full intent. That's kinda undebatable and if he hadn't encountered Itachi or met with the Kage that's what he'd still be doing now.
He went to the Kage meeting planning to follow Danzo afterwards and kill - or question - only him. He was not planning to attack the summit. Tobi and Zetsu foiled that plan purposefully to put him in a situation where he has only one option - to follow them. The Kages went after him, with intent to kill. At that point he was pushed into a corner. Even so, he abandoned the battle to run after Danzo, and did not try to continue fighting the other Kages - though they kept attacking him. That part I kind of understand actually.
What is harder to grapple with is his behavior towards his teammates - both from Taka and team 7. He was unbalanced and raving - but that's just it - he was not rational at that point. The only person who was able to bring him some sanity and clarity was, again, Naruto with his promise. If you have ever dealt with people that have a mental illness (and I have) you would have known that their perception of reality and reaction to triggers are unpredictable and often radically different than that of the "normal" person. They perceive the world and people differently. But a lot of the time such conditions are treatable, maybe even curable. Why not try that route first before taking someone's life?
He's got much better recently of course- but i'm just stating why Sasuke's revenge isn't over. It's a key theme that Kishimoto is addressing and even plain out said it with Shikamaru, whether Shikamaru was morally right or not in his resolve doesn't matter- I was just answering the question.
I have no doubt that his revenge quest isn't over - his resolve will only be strengthened - I very much doubt if Orochimaru, the master manipulator, would have let him talk to the Kages if he were not completely certain of the outcome. That said, he may still want to take revenge against Obito and Madara, so I can easily see him go against them, then against Naruto.
And you also forget an important contribution of his - helping Itachi stop the Edo Tensei. That alone can more than balance his negative score with the Shinobi world (recall Oonoki exclaiming that whoever stopped the Edo Tensei is a hero of the aliance, no matter who they are...).
