Have you seen an old man without an heir but has a reasonable amount of bitcoin, not too many, just enough???
There are people like that out there, I have heard of one, seen another, the old man has a heart condition and he just wants to rest, this things happen, mosts of his funds are in charity, he just wants to live out his days peacefully, his investment were done by another person, not something I would advise anyone to do, but his investments were done by another person, and now he has sold everything and just wants to live out his days in peace. You can't just rule out the possibility of these things, things happen.
Not having someone as an heir is not impossible because so many things in life is about choices and some persons might just feel they are better of they are just the only one or some sad circumstances made it unfortunate for them not to have anyone around them, but however that's not even a reason for us to have a conclusion that anybody found to be on that situation will not like to continue investing or holding for longer time on Bitcoin because even if they decided to sell is still the same circumstances if they hold it, however a lot of people feel fulfill having people succeed from there empowerment through there Bitcoin they invested for years.