If I want a conversation to be private, I set expiring messages, for the rest of it, I want to be able to go back and reference things all the time. Whether it be digging up a song link I sent a buddy, or looking up the address someone sent me a week in advance.

If they can't operate or are unwilling to operate under those guidelines then they just aren't ever going to replace whatsapp with the general populace and the community should start work on something else or agree that telegram is "good enough" (I don't think it is).