I mean, they are so rich, they can start to mine Bitcoin, even if they lose some money they shouldn't care, they are ok with all those money they already have.
Am I wrong?
If you became rich and you are doing the dream life that everyone wants is thanks to Bitcoin, don't let him die.
The answer to this is they are simply not that greedy. On a more serious note, if all the bitcoin in the world will go to only one person, do you think people will still value it, knowing that only one person has it all? I don't think so. Bitcoin will lost it's value if it's only owned by one person.