grant_k: When turning left, you normally don't have to give way to anyone. Except in the situation when this specific rule applies.
Further, our road code has long had the "Right-Hand Rule" which means that everybody turning right, gives way to all other traffic. Except in the case where this specific rule applies.
But that's the whole point! If people turning left had to give way to noone, then that creates an unfair level of priority in their favour. On the flip side, if right hand turners have to give way to everyone then you will have huge queues of vehicles waiting to turn right at the many moderately busy intersections where there is no dedicated green light for right turns.
Good traffic management requires that everyone has a fair chance to cross through an intersection, so shifting the balance of priority from left turning vehicles to right turning vehicles makes sense.
I can understand that the current rule can be difficult for tourists or inexperienced drivers but personally I haven't ever found it difficult except when I was inexperienced myself. If I am turning left and I am unsure if a vehicle coming up behind me is going to wait or go around me then I just slowly creep forward into the turn and I can stop in an instant if a right turning vehicle begins to move. If I'm turning right then I have a very clear view to judge what cars coming up behind left turning vehicles are going to do.
I'll admit to having my fair share of near misses, but none of them were the result of the current right turning rule.