The official "reason" is that Konan thought the Rinnegan was really Nagato's and considers it a national treasure of Amegakure.
Of course this is true... but also even if they were destroyed then as we still haven't known all about Rinne Tensei then Kishi would have use it to rebuild/recreate Rinnegan eyes along with Reviving Madara into ET body... so it would be even worse as Madara would have double Rinnegan from get go.The official "reason" is that Konan thought the Rinnegan was really Nagato's and considers it a national treasure of Amegakure.
Yeah, it's just a plot thing. In hindsight we see that she should have destroyed the eyes, but at the time she didn't know what we know now. Here's what Konan knew:If Konan just destroyed Nagato's eyes when he died? Why did she try to hide them? I'm fairly certain she even says to Obito she knew he'd come for his eyes.
Makes no sense
^^^ This. another one...Oro told Jiraiya to killed the orphans...that could've avoided a lot of trouble as well. Hindsight is 20/20Yeah, it's just a plot thing. In hindsight we see that she should have destroyed the eyes, but at the time she didn't know what we know now. Here's what Konan knew:
1) Nagato was a very good friend, and his remains needed to be honored (and hidden), not destroyed.
2) Tobi was going to come for the eyes.
3) Tobi could be defeated, because Konan knew about the timing limitations of his Kamui technique.
4) Konan had prepared extensively to kill Tobi by preparing several million paper bombs and a technique that would explode them over and over again for a time period longer than Obito could stay intangible
5) Even if Obito defeated Konan in battle, Nagato's body was hidden.
Here's what Konan didn't know:
1) That the eyes didn't really belong to Nagato, they were transplants from Madara (therefore, they didn't need to be kept and honored with the rest of Nagato)
2) Tobi also had a second Sharingan, with Izanagi
3) Tobi had Senju AND Uchiha powers, allowing his Izanagi to outlast Konan's explosion technique
4) Tobi had powerful genjutsu capable of forcing her to reveal the location of Nagato's body
5) The real Madara would eventually be resurrected and would need the eyes back in order to destroy the world.
Yes, if Konan knew then what we know now, she might have made a different decision. Unfortunately, she didn't know these things so the decision she made seemed right at the time but now it looks stupid. Here are a few more examples of where people might have done different things if they knew what would happen:
1) Obito would not have joined Madara, if he had known that Madara would betray him and force him to use Rinne Tensei at the cost of his own life
2) Kakashi would have "finished off" Obito, if he had known Obito was going to survive and become a major villain
3) On a number of occasions, various ninja could have attempted to kill Kabuto, if they had known he would eventually summon Madara with Edo Tensei
See? We can't look at Konan through the lense of what we know now. She didn't know all these things would happen so she couldnt' have made the correct decision.