I find this ancient topic both interesting and at the same time, non-sensical.
The highway code of "ikut kiri kalau tidak memotong" or literarily "keep left when not overtaking when the road is clear" was probably raised to provide a guideline to motorist on how to behave when they enter the expressway or dual carriageway. In this context, it is logical and good driving manners to stay in the left lane when you are not overtaking a slower car. It ensures that there is no hogging of the road.
However, when highways and expressway expands in the numbers of lanes, the stay left when not overtaking may not be applicable or practical at all.
Obviously if you are in the middle lane, and being the inner lane is empty and clear ahead, you are to drive on the inner lane and let faster vehicle passes you on the middle lane. However, if that was the case, what would be the purpose of the right or outer lane built for?
To be used for cars overtaking cars that are itself overtaking slower cars in the inner lane?
There are many hypocrite out there who loudly shouted for folks to follow stay left when not overtaking even though in real life situation, staying left most of the time never existed.
I find folks wanting to appear lawful but in fact they themselves are patron of mild-unlawful act such as driving on the middle lane. How many would have sworn that they always stay on the left even though the middle and fast lane were empty?
Such law are there as a guideline for motorist. Practical and commonsense should prevail when driving on the road, expressway or highway.
Don't be a oxy-moron or negative obediently following the "holy lawful imbeciles!!"
Silly indeed...!