Because I understand the word “simulation” to mean an algorithm which can answer questions about the states of the thing it simulates; not something which actually performs those same processes. The simulation of an Boeing can’t actually fly actual people to actual America. Why should the simulation of a brain actually experience actual qualia?
The problem with this argument is that an external observer cannot tell apart the output of a simulated mind from the output of a real actual brain, other than by looking at its substrate. Thus, the simulated mind is sort of like a zombie: it will talk about its own subjective experience, but the only real basis to that claim will be a portion of its algorithm.
I think it can still be argued that subjective experience is physically “real”, on Occam’s razor grounds: but it’s not an easy claim to make.
The problem with this argument is that an external observer cannot tell apart the output of a simulated mind from the output of a real actual brain, other than by looking at its substrate. Thus, the simulated mind is sort of like a zombie: it will talk about its own subjective experience, but the only real basis to that claim will be a portion of its algorithm.
I think it can still be argued that subjective experience is physically “real”, on Occam’s razor grounds: but it’s not an easy claim to make.