IMHO I applaud the retirees that want to continue to work. It's keeping them going and active. And 9 out of 10 of those jobs are jobs that some younger people might consider "beneath" them. So, for all you retirees who still want to work and are working, whether out of boredom or not, I applaud you.
Every human being, not matter what age, has something good they can offer their community. I, for one, would go nuts if I didn't do some kind of work. But, believe me, I leave lots of time for pleasure. ;D