It's a city simulator, not specific city simulator or even close. It is not accurate either as accuracy was not the main goal, but fun.
Human brain is a very specific and complex brain which we do not understand - vastly less than even cities at any scale. And to produce any useful answers, the model has to be accurate to some degree - and we don't know how much.
HBP indeed had no question which it tried to answer - it's more like climbing a mountain because it exists.
I have no problem with calling SimCity a “whole city” simulator. Why? Because we have a good functional model of a city. We understand its operation on any level. Not the case with the brain.
Human brain is a very specific and complex brain which we do not understand - vastly less than even cities at any scale. And to produce any useful answers, the model has to be accurate to some degree - and we don't know how much. HBP indeed had no question which it tried to answer - it's more like climbing a mountain because it exists.