If I was on my deathbed (and not married), I would give my passwords to my family and/or friends and tell them to empty the airline and hotel accounts. Heck, I might even ask for a phone and start booking trips for them.

Most airlines and hotels do not allow points/miles to pass as inheritance because they see death as the ultimate breakage opportunity. As for divorce, I think the potential problems from contentious separations makes it unappealing for the programs since they would need a desk of reps (extra overhead) just to handle everything that comes from divorce cases.