The high handed verdict and sentence has been handed the Korean pilot and his first officer. We may not know why or understand why they had not gone around if ATC had ordered them to. However, taking account into the Korean mindset, any missed approach would have cause him to get into a low fuel situation. He was not articulate or had the presence of mind to declare that doing a missed approach may cause him to be a " mayday " case himself. Koreans are basically silent types who do not simply broadcast their problems UNTIL ABSOLUTELY NECESSARY.
In his mind, he can't see how by going around he could really facilitate that much faster the Qatari plane can get to the ground. Given the fact that the A320 is slower but not by that much unless the B777-300ER was making a flapless approach at flap up speed to short finals.
There was probabaly a communication problem. ATC ZSSS should have simply order him or vectored him away without all the unintelligible Chinglish mutterings; I am certain the Juneyao crew would have complied or at least declare their intentions to avoid their own possible fuel " mayday " had they have to go around.