Also, when you're staring 55 in the face and you are fit and well, it does seem too young to retire. There is a certain value to staying where you are and working for the "devil you know", especially if you own your own house in HKG. It's not all about money. In 2003-6 many pilots went from the 747-400 back to the 747-200F on a much lower salary for a few years until the RA65 came in and they went back to the -400 on original conditions etc. At the time it was an excellent deal and those pilots were employed usefully for another 10 years. It was a transition time and, of course, some FOs were delayed in getting Commands. It happened in Airlines all over the world too.
Things change and - of course the comment about Viagra may be relevant too. If you expect senior guys to retire early when they don't have to, I think you're deluded and you probably would do the same as they are doing.