A lot of Steam customers simply haven't thought very far ahead: what happens when they die? As a twenty-year old company there is certainly a reckoning on the horizon as their users age-out and start passing in higher numbers.
What happens when Gabe Newell dies is another very important question that adds some urgency - one or two decades - to establishing more balanced policies.
Steam says they won't pass the library to heirs, but steam will do whatever the probate judge tells them to.