Really? Man, ageism sure is rampant in the rock world. You don't see comments like that in the world of jazz, classical, world music etc. Never ceases to amaze me. We should all be in as good a shape as Mick when we are in our mid 70s. Don't see him in a walker or wheelchair anytime soon.
If they still love what they are doing and have such an amazing catalogue of music to play, why not keep going? Are you the arbiter re what time someone should retire from their profession? All power to them I say. Enough with the snide ageist remarks people. Whether you are a musician, painter, dentist, lawyer whatever, if you are still good at your job and love what you are doing, keep on going. I love my work and am in my early 60s and have no plans to stop anytime soon.
Rock on Mick and the boys.