Don't you just love the CAA clinging to arbitrary regulations.....resulting from their "discretionary powers"?
They will quickly point out the presence of "waivers" to the rule or regulation but then immediately tell you that is not their policy (granting waivers as set forth in the rule/regulation).
Bottom line....to make any changes requires some Jobsworth to make a decision that can be tracked back to him and thus be held accountable for having made that decision.
It is far easier for them to point at the rule, reg, or memo and smile and say "Nope! No...have to follow the rule here!"
There are Offshore pilots in their mid-70's and who have had hip replacements still flying in the Gulf of Mexico. As long as they can fog mirrors and toddle to the aircraft and remember how to find home and pass a class II medical exam....they are good to go in the FAA system.