I respectfully disagree with this argument. There is no reason why, on the right lane, you should give way to a vehicle faster than your own if you are driving at or above the speed limit.
At the most fundamental, the law states a driver cannot go over 90, regardless of whichever lane you are in. So, even if a driver is overtaking, he cannot go over 90. That means, if he comes at 170 from behind and even if I am doing 90 only, I don't have to assist him in breaking the law by giving him way, and by law, I am not road hogging, because I am going as fast as I can legally.
But let's talk real world: the right lane is for speeders. And all speeders are there on the right lane because it is the fastest, not because they are using the lane to overtake anybody. So where's the validity of "keep left unless overtaking"? If a driver keeps left because he sees a driver coming from behind at a faster pace, he's merely being gracious.