As mentioned this is about the CAA, not the airlines and not the doctors (it wont effect the medical tests one iota).
Some years ago a helicopter pilot took the CAA to an industrial tribunal over being barred from single pilot operations at 60 (more an issue with rotary). The CAA accepted that the risk of incapacitation at 65 was then far far less than the risk of incapacitation at say 50 just a couple of decades before. Therefore raising the age to 65 or 70 etc would actually result in a still lower risk than we had had just a few years before. However, they won because they argued they could not afford to examine the evidence and were not obliged to change rules just because medicine moved on or pilots lived longer.
This is a really unacceptable situation, where an individual's career is cut short simply because of something that applied 30 years ago and where the regulator agrees there is an acceptably low risk and just cant be a@@@@@@@ to do their job ie set rules against facts. It is not the only example where the regulator runs against good medical advice.
I fully accept some want to retire before 65 or even earlier, but nothing will prevent this. It is about the freedom to choose. For others it is their livelihood and not uncommonly they need the extra years to provide financial security in retirement. For the newer generation paying their way through training and with years of low salaries this may be more important than we think.