I love that you think this is true. It shows just how judgmental and out of touch you are. Sure, there are some people over 65 who have an inordinate amount of money, but to say they aren't contributing is akin to them saying young people are useless.
Many of us are invested in learning and working. Many people retire to begin their entrepreneurial adventures and giving back to society. I started a business at 60 and donate regularly. I hope to employ others along the way, but for now, use contractors to handle things they are better suited for.
And, I don't think I'm the odd man out. Many of my friends and colleagues are well over 65.
Covering yourself by saying it is a gross overgeneralization, then going back in for more digs ... tacky.