Why do you have your position on destructive uploads

Mostly by comparison to non-destructive uploads. Copy my mind to a machine non-destructively, and I still identify with meat-me. You could let machine-me run for a day, and only then kill off meat-me. I don't like that option and would be confused by someone who did. Destructive uploads feel like the limit of that case where the time interval approaches zero. As with the case outlined in the post, I don't see a crossed line where it stops being death and starts being transition.

Now that I've written that, I wish I'd thought of it before you asked; the two are really mirror images. Approach destructive uploads from the copy-then-kill side, and it feels like death. Approach them from the expand-then-contract side, and it feels like continuous identity. Yet at the midpoint between them they turn into the same operation.

In a world where everyone is uploaded or Star Trek transported each day, you could believe that the world is inhabited by day-old people who will cease to exist on their next transport. I couldn't prove you wrong. But it wouldn't be a productive worldview.

Who cares? Don't appeal to social norms. For the person about to step into teleporter, there's a true difference, even if it not observable from the outside.