People that actually work for a living, like tradesmen, are simply broken and can not work past 65.  Paper-pushers, perhaps not.

Having worked a long and hard life, it's evil to penalize them for being broken due to that work, so the age should remain at 65.

However., there is a strong incentive to keep these knowledgeable people in the trade to instruct and help others, so why not give the business that hires them a tax break as an incentive.