I am not saying that age causes a person to sell bitcoin earlier than expected, but age could be a factor that affects whether or not a person has at least a 4 year timeline so that they would be an investor rather than a trader, and sure they might still be willing to trade, but it becomes risky for anyone to try to trade less than 4 years, even though people may well be willing to take those kinds of chances, which I also would consider to be gambling rather than investing, but people do those kinds of things, yet if someone is really unsure about being able to have enough resources, they may well not want to get into trading with money that they pretty confident that they are going to need in less than 4 years..
I think so too, if they are old, it is possible that the investment they make is not for themselves but will be inherited by their children at some point in the future. That way I think that relatively old age can invest for their life or death without feeling the results or lifelong investment because it is a fact that many of them will inherit investments for their children.
That does happen, there is no disputing the fact that parents often do investment on behalf of their children. But how about in a situation where a parent wants to divide his investment in bitcoin among his children before his demise. Because he has realised that if he doesn't do it himself that it will cause a big trouble among his children in his absence. Such a parent who is already getting old will definitely adopt the shorter holding period of 4 years. In this case we are taking about elderly people who makes investment for themselves. So as @JJG rightly said, old age is major factor that often influence the choice of holding period in bitcoin investment
If the time period is less than 5 years, of course they still want to enjoy the results of the investment they make. It is possible that they will not switch to trading practices because old age may make many mistakes and of course it will be quite chaotic if they reverse the direction of investment practices to trade.
If you read carefully about what @JJG is talking about, you will understand he's saying that, if you know that the money with you, that you intend to use and make investment, is the money that you are going to need or use in less than four years, it is better to keep that money till when you will need it, rather than going into trading. He is not in anyway suggesting that because of old age that people should reverse their investment and go into trading, no he never said that. I took my time to read between lines of his post, what you are suggesting was not in his post.