I disagree based on the premise that Itachi could have went rogue before that took place. He would have most likely still have joined Akatsuki anyway. He could have walked away from it all. Either way he would have been exiled from the leaf. Why kill your clan and get exiled anyway? I am not saying Itachi is bad but saying he isn't wrong, especially morally, which isn't naturally subjective, is quite stunning in a bad way.
Walking away can be an understandable choice but that's avoiding to take a decision and still allowing terrorist attack on rest of the village and let people die. Clan could still end up dead either way. Without Itachi and Shisui they were out of their two biggest guns. Not all of them were exceptional or Obito and Itachi would have had more trouble. All in all both sides would have had major causalities and lead to attack from other clans. If Uchihas were expecting a few deaths on their part a way to advance themselves I do not know. But then whole situation could just become worse and go back to pre village formation situation.
Your idea of morality is from a different time, culture and values which is more individualistic. But there is another school which goes by the idea of "greater good". Clan VS country. Death of one problematic clan vs rest of the village. One can walk away from the group which is more wrong or more violent or with more narrow thinking and ensure that the matter ends with minimum loss of life. Itachi did his duty as shinobi of Konoha to the best of his ability. Personally he literally punished himself.
That said it was not a perfect plan. In all this Sasuke was the causality twice - he lost his parents and clan and at the same time he became the killer of his brother. So the whole situation got more messed up. He wanted Sasuke to be a hero but that part of the plan failed. Only Sasuke connection with Naruto and team could salvage the situation. So he failed on that account.
Also, Itachi was a brilliant idealistic shinobi but he was barely 12-13 when he was forced to make such decisions. It was a bigger failure on part of Hokage and Fugaku Uchiha to put him in such a situation. Pressurizing him to betray the force he joined and spy for clan and participate in civil war for it, was not the best parenting either. Itachi was totally trapped and they exploited his idealism to the max. He was more idealist than his father realized initially.
Seeing both him and Shisui felt strongly against being used for clan politics to undercut the organizations they worked for, Uchihas were not being saints either. These kind of actions in multicultural system do not increase trust factor either. It promotes the idea of them vs us even more.
I mean, I don't think it's morally high exactly either but coming to the conclusion that you must slaughter every single member as a result is not really morally high either. If we're talking about morals, I don't think the answer was to attack the clan or attack the village which is why I think Kishi dropped the ball. He didn't really convince me that those were Itachi's only options.
But when I said it was cucked to choose your village over clan, that was more of a personal thing for me, I realize most may not agree and like you said it's subjective.
Killing whole clan being not so great is a recent concept in history. If someone betrayed the King, whole clans including the servants have gotten penalized or eradicated completely. And this "idea of my own clan and community comes first even if it's wrong" too is not exactly called ideal in all schools of thoughts.
