While i dont necessarily agree with you, it is not my point. I am not saying we should limit the speed according to local speed limit, just that there is no reason ever for an individual car to go above 150kmh (or whatever the highest allowed speed in a country+15% is)

Speed limits are set according to a number of factor from noise, local crash history, density of pedestrians, threshold of the safety equipments (such as rails) , willingness of the governing body to review it, etc While some are not good, I would definetly argue that not all the reasons can be assessed from the driver perspective.