Speed limits have come under increasing pressure from politically correct but uninformed campaigners who blame drivers and excessive speed for any accident on the road. There are clearly roads where skilled drivers are capable of safely driving at a higher speed safely but which have been designated 40mph or 50mph limits in the interests of safety.
If 'trained' drivers were allowed to exceed speed limits it is likely to encourage more people to take up 'secondary' driver training (I hate the term 'advanced driver') allowing them to get from A to B more quickly but safely. It would have a positive effect on road safety rather than the oversimplistic suggestion to raise speed limits on motorways; I know plenty of people who are dangerous drivers regardless of the speed they drive at.
The obvious counter argument is that the boy racers will just use it as an excuse to speed, but they do it anyway, and a trained driver is easy for a Cop to spot and therefore ignore, making their job easier to prosecute the drivers without secondary training.