I like to look at all angles in discussions like these, not necessarily because I disagree with the general consensus, but merely to raise other points of view to see opinions or whether anyone has considered this.
So in light of that, has anyone thought about the reality of expecting a slow moving vehicle to continuously pull off to the side of a 1 lane each way road to let faster moving traffic by? There aren't many roads these days that arent busy all the time so is it fair for a vehicle that either doesnt have the power, or a driver sticking to his/her skill limits, to be doing this? Consider the status of road shoulders in general. I am not saying that people shouldnt pull over but for some drivers this could be dangerous. Merging is not a driving skill that Aussies are adept at for the most part.
People should drive to 4 things in no particular order: road & weather conditions, their own driving abilities, the limits of the vehicle they are driving taking due consideration of whether they are towing, and the quantity of traffic they are sharing the road with.
Its a lot to expect of most drivers to be on top of these things AND worry about pulling off the road every time they see a vehicle in their rear view mirror.