[stephanfroede]

The conclusion is that you need the quantum "layer" to get a intelligent machine.

Not the simulation of quants. Could be much easier than trying to simulate everything. Google tried to use DWave quantum computers for pattern matching in Google Glass.

But there is a debate that DWave computers are really quantum computers, some say they are not quantum computers.

[crististm]

You might not need the quantum layer, then again, it might be indispensable. The thing is: you don't know. And without considering all the effects you have at atomic and subatomic levels, you can't say that you simulated a brain. All you can say is that you simulated something that looks like a brain. Which is completely different.