For a variety of reasons people don't always retire at 68. I know my husband (in a different trade) works with people in that age group. Some want to work until they die, some have an ex they don't want to pay out on retirement, some are on their second marriage and have kids in college to pay. I could go on but just because you can retire -- doesn't mean everyone does.
It also doesn't make the fact that the baggage handlers are longshoremen not true.