Rushing to close a deal on a high value asset such as a boat, aircraft, or real estate where the seller insists on actual cash. Granted, you should probably use some form of durable check, but some buyers want actual cash. There are also cultural business habits in some ethnicity/national backgrounds to prefer actual cash over safer bank instruments.
It really doesn't matter: if someone wants to carry a large quantity of cash on a plane, this is still an open society and freedom must be defended.
Wouldn't you withdraw your cash at your destination to avoid the obvious and huge risk of your luggage being lost?
I agree there probably are times that it happens, but it's very unlikely. There are much better examples where the police steal large amounts of cash even when there's an obvious legitimate explanation.
It really doesn't matter: if someone wants to carry a large quantity of cash on a plane, this is still an open society and freedom must be defended.