"When a distinguished but elderly scientist says that something is possible, (s)he is almost certainly right. When (s)he says it is impossible (s)he is very probably wrong." - Arthur C Clarke
The reason these scientists are upset is because we are no where near being able to do this. They're not saying we can't do it someday, just that it's a crazy waste of money right now. We don't know enough about the brain to make reasonable full scale models of it yet.