A kage going down is basically the equivalent to some antagonist offing the Master Commander in Bleach handily.
I agree with what you said about the character and his/her importance to each individual reader, however, I do not agree with this assessment for a multitude of reasons.
The Kages, as a group, are relatively new to the series. Three of the kages we know were only just introduced in one of the most recent arcs. Two of them are characters that no one has grown to love in comparison to Gaara and Tsunade, and one of them a lot of people genuinely like (A) because he's had character development and such. The Captain Commander, on the other hand, has been in it since the earliest of the Soul Society arc and we do not know his story or background yet. I really wish that Kishimoto would have shown us or given us a glimpse into who the other kages were early on in the series. Now? Their deaths hold no meaning to me.
The Captain Commander represents soul society itself. He has been the captain for a thousand years, and he is who is associated with Soul Society. These kages are simply following in the footsteps of their elders. The Captain Commander IS the giant that these current captains are standing on. "Over the course of 1,000 years, no shinigami has been born that is stronger than I"
The Captain Commander holds much more weight than these kages apparently do. Do you see how Madara looks down on all of these guys? He treats them with no respect despite the fact that he was never a Kage himself, and that is a position that he once revered! He's basically saying "
You are the kages? You are not fit to be kages." In Bleach, even Aizen respected the Captain Commanders' strength. Fucking Aizen, the most vain, self centered guy in the world admitted that the CC's strength exceeded his own. He is the most respected person we have seen on screen in all of Bleach. People of the higher order in Naruto do not respect the kages, it seems.
All of these comparisons I'm making are in the context of each respective world, of course. But if a comparison MUST be made, I'd say that a kage going down is similar to a captain getting killed in Bleach.
Squall ASF said:
Now while it is a bit lame in respects, in context of Naruto's story, we needed to see the fruits of Naruto's power upgrade labor and he needed to make his presence felt by the entire ninja world. Everyone will owe him one and look up to him when this is all over, not just Konoha.
Oh come on. You can't be serious here. Naruto's growth could have easily been shown without him stealing fights and trampling everyone else's sacrifice. This is akin to you saying that Naruto's growth could be shown if he helped out Shikamaru, Neji, Chouji, and Kiba individually during the rescue Sasuke arc.
If Ichigo were to jump into each Captain's fight just to show his growth, that would be stupid. And it's also dumb as shit in Naruto. There are plenty of fights reserved for Naruto that show his fighting growth. Take the Pain battle for example. Tobi? Dr. Snake himself? These are all important fights but just as important was everyone elses battles and the fact that Naruto is single-handedly coming in to fight on their behalves is unforgivable in the context of a "war"
They are to protect Naruto. Similarly, this was held true in Bleach:
http://i.imgur.com/gV1QX.jpg
Ichigo didn't step into anything he had no business stepping into (despite his wishes). He sat there on the sidelines and let everyone do what they needed to do until he was needed. This idea of Naruto having to jump around everyone trampling on the pride of those who want to protect him just for the sake of plot or to shoehorn Naruto's "growth" is very stupid. ESPECIALLY in the context of a war. And the bad thing is that Naruto's war is more war-like than Bleach's FKT arc in the sense of its scale, and yet this fundamental idea involving the protagonist and his involvement in it has been completely missed by Kishimoto.