I have had what I call orphan miles or hotel points expire over the years.
If some has 10 flights in a year but flew, SW, United, Spirit, AA, Delta and Jet blue using Orbitz to book the cheapest flight I can see where airline miles can be lost, but they might have signed up for the Orbitz rewards program.
Personal Cards: Amex Plat | Amex Delta Res | CSR | Citi AA Exec Business Cards: Ink+ | Amex BGR
I think there are probably two factors here. The first is, it is (broadly speaking) probably fair to say that middle-aged people pay more attention to financial details than younger people.
But also, I think points and rewards have gotten more common in recent years than they used to be, so older people have probably not had as many opportunities (especially in their own younger years) to let points expire.
