Looking at that picture of General Patton in a previous post, it occurs to me that game protagonists are rarely, if ever, old. James Bond might be the only character over 40 that I've ever played as in a video game. Of course, I don't play slow-paced detective games.
It makes sense that the majority of protagonists would be young, just as they are in films. Young people have more mobility, sharper reflexes, room for new romantic relationships, more to learn and more to discover about themselves, etc. But is this lack of elderly player-characters an odd gap?
Some elderly traits could make for interesting story elements and gameplay twists. For example: long and tested relationships, a focus on younger generations, limited ability to flee or pursue, a patient pace, extensive familiarity with certain places and things, a value system at odds with current events and culture, preference for old tools and strategies, etc.
It's not that I think old people should be represented. I just think old protagonists could offer gameplay not possible with younger characters. It's a possibility to keep in mind when starting a new game.