Around 1950, people entered the workforce at 16-18 and shuffled off this mortal coil typically at around 70.
In 2010, people enter the workforce at 21-24, and shuffle off typically at about 85.
The medical profession has also come along an enormous way in its ability to tell you what's wrong with you (or not).
We all need somehow to have our retirements paid for out of some income, from somewhere.
Any way you look at it, retiring people at 60 or 65 makes absolutely no sense any more. It's an anachronism.
Personally, sat here in my 40s, I don't anticipate retiring this side of 70, but nor do I hope in the 21st century to die this side of 90. So I'll probably still have a longer retirement than my WW2-era grandad did, who retired about 65 and was dead by 70.
That said, make the ambitious co-pilots happy by replacing promotion through seniority by promotion through examined ability, and perhaps everybody gets what they want (or the old chaps will be proved right about the abilities of the young chaps...)
G