Um, if you look at Obito as not having any ideals of his own, then sure I guess. But he clearly thought what he was doing was right, just like any soldier would think their country/government, etc's reason for fighting is right. In fact, he thought what he was doing was right for the whole world, he was basically trying to build paradise. In war there will always be winners and losers but you can never really say that anyone's right or wrong. Obito was just doing what he thought was right just like Jiraiya Kakashi, Minato, Hiruzen, etc etc probably did when they killed anyoneYou kinda ignored the rest of my post. In wars there is usually two sides each fighting for whatever reason in behalf of their country to protect it and their country's ideals. Each side is blood guilty so it is illogical to single one person out when you r guilty of the same thing they r.
Obito on the other hand was just a plain murderer for his own reasons. (Murder is personal) What Obito did was much worse than a soldier in war, but my only point is that ppl r justified to be offended to what Naruto said. If Lee, Hinata, Shikamaru, or Ino were there I would expect them to be offended too.
Also once again they shouldn't be offended because Naruto isn't saying he's awesome for killing people. He specifically said it was because he wanted to be Hokage