Malkionism provides us with a detached and abstract philosophical approach to Glorantha. It is easier for us Westerners than the raw personal experiences found in most rune cults. With Malkionism we can reduce mythology to patterns and processes, or esoteric facts to be discussed or disputed, rather than psychological events to be experienced.
In short, most readers likely approach Glorantha like the Malkioni. Most players and GMs approach it like the Orlanthi or Pelotians or Praxians. Ponder that!
But the Malkioni strive to know, to analyze, to comprehend. One of the aphorisms attributed to Arkat was “to know the unknowable is not only impossible but futile. The unknowable can only be experienced.” And experience he did.
The Malkioni perspective makes the overall structure and patterns of the cosmos easier to grasp and use. It is not tainted by an elemental bias, but can see all with detachment. The downside of that detachment is powerful Rune magic is hard to access, and the Malkioni must rely on their sorcerers for powerful magic.
The problem with Arkat is never that he was wrong but that he was right. And his successes certainly suggest he might have been.
His betrayal of cult secrets to others and his opportunistic willingness to make any alliance that seemed useful against Gbaji is a reason for him to be hated still, but does not discredit his insights.