I suspect most people that would say that they wouldn’t kill Grandma would also say the same about a situation where they can kill someone else’s grandma to give the money to their own family. Actually, in the hypothetical, you’re not one of Grandma’s heirs, so I interpreted it as if you’re some random person who happens to be around Grandma, not one of her actual grandchildren.
So really, I think that it is either something like “the moral weight of the person next to me versus distant strangers” or “choosing to kill someone is fundamentally different than choosing to save someone’s life and you can’t add them up”.
I suspect most people that would say that they wouldn’t kill Grandma would also say the same about a situation where they can kill someone else’s grandma to give the money to their own family. Actually, in the hypothetical, you’re not one of Grandma’s heirs, so I interpreted it as if you’re some random person who happens to be around Grandma, not one of her actual grandchildren.
So really, I think that it is either something like “the moral weight of the person next to me versus distant strangers” or “choosing to kill someone is fundamentally different than choosing to save someone’s life and you can’t add them up”.