Hmmm, I'll buy that. Perhaps Harry's requirement being, well, really required was a key.
I still contend that other people might have really really really needed to find something that others have hidden, and that there's no big logical leap needed to go from "what a great place for
me to hide things" to "what a great hiding place."
From what I understand, the Room of Requirement does not make a moral judgment. If Harry needed the diadem tiara to destory Voldemort, I don't believe the "Room" fullfills that request with any more preference than if someone needs the tiara because it perfectly matches the gown they're wearing to the Yule Ball.
