Naruto hasn’t sacrificed anyone though, and that is where you seem to be running into issues. Yes, he isn’t willing to allow his lovers to suffer to insure some strangers’ happiness, but that isn’t the same as allowing those masses to suffer to insure those of his lovers. Naruto had a plan when it came to extracting Yugito, and if it failed, he would have faced the consequences of it failing. Such as turning himself over to Kumo. Would that still stop a war? Maybe or maybe not, but using the wellbeing of strangers to justify Yugito needing to remain in Kumo is not something Naruto could have done if he is going to claim to value his lovers.
Their goal is important, but at the same time using it as justifying making them suffer is not acceptable either. As I stated before, Naruto started the goal but he didn’t really realize what it would entail. He also didn’t realize how important those women would become. However, that doesn’t mean he recruited them as soldiers and thus can spend their livers frivolously. It is still the driving force, but again it doesn’t justify him sacrificing them or their happiness to achieve it.
If that is how you want to view it then be my guess. Yet, to me a defining something as a tool is often the view point of the people doing the using. To me, your collective views Naruto as a tool because it was fine for him to be turned into a weapon for their sake. His father also turned him into one because Konoha couldn’t be without its weapon. Naruto doesn’t see his lovers as tools and I don’t imagine they do him. He sees them as partners in the endeavor and partners deserve to be rewarded equally when it comes time to collect the reward for one’s actions. If the end goal is a peaceful world, then Naruto is seeking one where not just he benefits, but his partners as well. As to the masses, well if they aren’t an active part of the attaining the goal why do they deserve to benefit as much as those that did. Shouldn’t the end result be good enough, why do Naruto’s partners not suffering to make what they achieve any less rewarding for those that simply sat on their asses.
The problem I have with Minato actions, which Gaara would emulate is, do we consider sacrificing children to be a good thing or bad thing normally. Well if it normally is bad, it doesn’t suddenly become acceptable because the stakes are different. If Minato wants to sacrifice himself, then he bloody well can do so. It stops being acceptable when he decides his wife and son should be used up as well. Yet, the Collective didn’t seem to broken up about a child being turned into a weapon for their sake. Weren’t they fine with Naruto suffering for them? Was it really too much to ask that Minato find a better way to prevent a child from suffering? Is it really out of the realm of believability for Naruto to want to make Yugito’s situation better and not let the concerns of people he didn’t pledge himself to sway his decision?
Ultimately, to me it seems selfishness as defined by you is an action that a person takes which can expressly be considered to society’s benefit. But, did society care in the slightest about Naruto’s situation. No, because he was sacrificed for its benefit. Naruto would have been willing to pay the consequences for his choice if it failed to mitigate a war. He was willing to do that because he cared for Yugito, and he didn’t want to cause needless suffering. But, he couldn’t let the fear of that potential outcome stop him.
I wouldn’t say my Naruto is miserable in the slightest, because although society doesn’t care for him. He has surrounded himself with people that do, and ultimately isn’t that what motivates most people to want to make the world a better place. Not to please strangers, but those closest to you. To me, happiness is ignoring what norms society would force on you, to do what you feel is right for you. You don’t want to get married and pop out kids. Then don’t. However, isn’t that what society would demand of you in order to perpetuate it. Naruto’s goal is to make the world a better place sure, but what good is achieving it if he loses his reason for doing so along the way.