Yes, I understand that selling a rented property can be less profitable than selling a property without a rent contract. But holding on to a property that generates no income is even less profitable.
Sometimes seemingly abandoned buildings are used for one-off occasions which generate income: downtown LA is full of "historic" buildings which the owners allow to dilapidate outside of a few areas they can rent out once or twice a year to a film crew.
edit: another thing -- rich people procrastinate too, in fact many of them can afford to procrastinate on matters like this, and they may rather take a loss than confront the anxiety and work of selling or renting out the property