How many years since AF 447 & simulators STILL do not represent correct handling at high altitude. It's criminal if you ask me.
Take that issue up with the airframe manufacturers. Simulators are only as good as the data available. If the aircraft manufacturer can't provide stall data (for example), because stalls aren't included in the data package, how can the sim manufacturer model the behavior? Certain extrapolations and modeling data may be valid, but remember simulators aren't magic - the underlying model can only be as good as the data provided.