I find it hard to understand why this is so difficult
I have to totally laugh at that statement because I was thinking that same thing not that long ago.
I think I somewhat understand their viewpoint now, but I don't know that there is anything I could say that they haven't already. I'll give it a shot.
Consider transteleporting a plant. If it was transteleported from the market to your house, you've got a plant, a clone of what was originally in the market. But what difference does it make? Doesn't it look and smell the same as the original? Isn't the original gone now? Who will it matter to that it isn't the original? Sure, you'd know that it wasn't the original plant, but so what? The original plant exists no longer and you have the only copy and it is a perfect copy. So it shouldn't matter to you, it shouldn't matter to anyone. It would be silly to suggest that it matters to the plant. But that's the path you're going down.
You'd say "yeah, but it doesn't have any identity/individuality/whatever" and their contention is that neither do you. You have an illusion of it.
What is the purpose of life? To spread your DNA? To make a difference in the world? That clone of you will take your place, will do what you would have done. It has your thoughts, your memories, your DNA. So what makes you different from your identical clone? Nothing. It's identical, or identical enough that it makes no difference in the outcome.
But it matters to the original illusion of self. The original is disassembled. The atoms continue to exist in another form, but the illusion of self attached to THOSE atoms is now gone. And that seems significant, but it isn't. It isn't significant to the atoms that used to participate in that illusion. That illusion of self exists now with other atoms, arranged to be your DNA. So that is fundamentally you, even though the original you no longer exists. To say that it matters to original you would mean your original illusion of self would have to exist outside of those atoms, and it doesn't. Your illusion of self does not matter, it isn't anything. It is only an illusion. Thus it should be able to accept that a continuation of the illusion in another place is sufficient for the purposes of the individual cells and the collective body as a whole, and that is the preservation of the DNA and whatever other purposes your illusion of self deems important. It may seem disquieting that it will be disassembled, but that's not significant when we're talking about something that doesn't really exist, is merely a construct for processing inputs.
