Though, I don't see either Nagato, Konan, or Naruto fighting at all right now. Nagato will continue his story about his parents, being orphaned, watching his village suffer over and over again, Yahiko's death, and his transcendence into Pain. After his story is over he'll most likely -
A) Die from over exertion
B) Become "Gay Friends" with Naruto. I hope this never happens.
Since Kishimoto is almost done with Pain's character, being a complete foil to Naruto, he'll be gone in the next couple of chapters.
I would agree with you had we not already have seen his prior idealism when he was with Jiraiya. Pain's logic was originally the same as Jiraiya's, to protect the ones he loved and to "grow up" in the village of strife and bring peace among his land. Somewhere along the line, that path was skewed and combined with Yahiko's ideology that people will only understand when the same pain is afflicted back towards them.I can only hope Nagato has something more serious in his past to merit the path he chose. Compared to Sasuke's flashback of what happened to him this seemed incredibly minor. Pain's logic is growing more and more far fetched to me, he is starting to look more and more like a child, just one with a lot of power. Itachi's story and the logic behind the path he choose seemed far more convincing. I was hoping Pain's story would show a similar level of broadened depth and show case the impossible necessity of the role he chose to take.
Thus is why there will be a flashback of Yahiko in the next few chapters, to explain how Jiraiya's, Nagato's, and Yahiko's ideas combined into one, creating the "Pain" character that we currently read.
I believe that it's a mixture of both. Rather than having a singular hatred for all leaf ninja after the death of his parents, he accepted and trained under someone from that country. I will agree that it is childish thinking to want to destroy the world in an attempt to save it, but what he may be saying is true. Pain's ideas stem from "What-If" factors, where he trusts that the very people that he scorns to play into his version of justice. If people are as I think they are, they will push the button and destroy themselves over.So far Pain's views seem to come from a place of deep personal trauma rather than a true concern for the betterment of the world as he claims.