...If that runway 13 was such a hasssle, why didn't they just use 31 and approach from the other end?...
Perhaps the prevailing wind had something to do with it?
R/W 31 was frequently used for landing, and as it had an ILS, it had much lower landing limits than the IGS approach to R/W 13.
Taking-off from R/W 31 however was a very different matter, due to the high ground immediately to the North of the runway, and so quite often, when R/W 31 was in use for landing, aircraft would still take-off, with a tail wind, on R/W 13.
This obviously posed a considerable problem for ATC, with aircraft heading towards each other, and resulted in a large reduction in the number of aircraft movements per hour that could be accommodated.
In general, provided landings were possible on R/W 13, that was the preferred runway, in order to keep the movement rate up, and to allow the larger aircraft to take-off at much higher weights than was possible from R/W 31.
The approach on R/W 13 was not actually "such a hassle" most of the time. Cathay Pacific pilots were probably the experts, with some Cathay pilots having flown it literally hundreds of times in their career without incident.
Most pilots I know used to look forward to flying the IGS approach onto R/W 13, and only when the weather turned bad - and it could turn very bad in HKG
- did it become more challenging.
The photos of some of the worst approaches are indicative of what can happen when inadequate planning and briefing is coupled with poor piloting technique and inadequate monitoring. Put bluntly, poor flying.
Most of those unstable approaches should have resulted in a “Go-Around”, and the photos of those that were continued to a landing are generally indicative of the worst possible flaw in an airline pilot, that of poor judgement.