I think the "hot topic" icon is inappropriate for this sort of event.
Looks like due to the displaced threshold they had no in aircraft pseudo glide slope, and no external visual glide slope like a papi. ILS also out due to works.
Before making comments about Korean pilots and visual approaches, some of the more challenging circling approaches I have done were in Korea, an the locals handle them very professionally. With weather conditions being so benign they may have let their guard down rather than doing a circling approach in bad weather.
It is possible they thought tey were above the visual slope and increased their rate of descent, in doing so autothrottle reducing their thrust back to idle, at a low altitude realising they were now low on profile raising the nose, reducing speed, increasing drag, and the engines spooling up from idle. Not enough time for the thrust to recover, the higher angle of attack now resulting in a tail strike on the sea wall.
No down force from the tail as it shears off, cg change, heavy nose gear contact, heavy main gear contact, possible slight thrust asymettry as the engines spool up.
Elements from the Air France Flight 296 at Mulhouse–Habsheim, and Turkish Airlines Flight 1951, low and slow with idle thrust is not recoverable at low altitude, and FedEx Express Flight 80 where a heavy landing will result in structural failure.