It used to be illegal to own gold for a few decades (started in the 1930s during the great depression). Therefore, for a lot of old people owning gold has a kind of psychological effect in that it was something forbidden for a large portion of their lives. Also, a large part of it is likely the enormous amount of commercials for people to buy silver and gold on TV channels that old people like to watch.

This is also a generation that has seen the value of the dollar plummet. One of the best marketing stories for precious metals I've heard is: "A quarter in 1960 could buy one gallon of gas, whereas a quarter today wont buy much. However, the silver in a quarter from 1960 would be worth about $3.50, or the price of a gallon of gas." It also comes down to volatility, old people are looking for a way to preserve wealth, not a way to get huge multiples and ROIs on their money.