Hey; if the boy is trying to make a better world, than killing the Kage may have been necessary. For the good of the entire flock, a few sheep may need to be sacrificed. After all, how many of those Kage are going to permit the disintegration of the Shinobi system? That's how they make their money. The entire Naruto world is dependent on the Shinobi lifestyle which is dependent on war, death, (in theory, in this case) stealth, and subterfuge. Honesty and Shinobi are kinda Oxymoron's...especially when certain villages still hate each other (like Iwagakure). Comparing Hitler to Sasuke is a little much (even though Hitler may have just been trying to make a perfect Germany; I can't fault him for the idea, but I can for proposing the method, even though if Germany hadn't listened or put him in power, that whole situation would've never got off the ground).
Granted some Kage might have worked together (probably just Suna and Konoha) but the others would've scrambled to get the tailed beasts (as they should; why work for peace when I can dominate the market?). If I was a Kage, my mindset would be to become the strongest village and establish peace by having all the villages under my thumb.....an idea that has probably ran through most of the others Kage's head (all except Tsunade because Konoha is the "Good" Village).
Sasuke fans are not deluded; in order for peace to truly exist, one must A) take away the War Toys (Tailed Beasts, Weapons and the Shinobi System), (B) Take away free will (via Eye of the Moon), or (C), my personal favorite, have one NEUTRAL, FANATICAL person (like Pain) hold all the cards and make an example out of one village (by destroying it, of course), therefore "encouraging" all other villages to play nice, and actively maintaining that level of control (squashing rebellions, sabotage, killing those who get too loud, etc.). It's not a pretty method, this is true, but they live in a shinobi world; you can't make an omelet without breaking some eggs.