But you're not "most of us". The sentiment is common enough that any attempt to distill human morality down to principles has to take it into account, or at least state outright "this system is at odds with most people's ideas of morality, and is designed to be so from the start".

Gal can - at need, or simply for fun - pop the hood and see the thing that pierces the illusion.

It's an analogy. If it's used for mind uploading or copying, Gal can't "pop open the hood" and see that she doesn't have continuity of identity with the original Gal.