The idea of a PLB is it lets rescuers find you, often at considerable risk to themselves, while you're still alive. If you're already dead you should not put them at risk just to find your remains.

The correct action for the pilot would have been get on the radio (or satellite phone) and tell someone on the ground that there was trouble.

Rather than a dead-man switch I don't understand why PLB's can't send more different kinds of messages than "I'm in unspecified trouble, send help immediately!". It could have a message selector that lets you choose between "This is an advisory update, my location is [coordinates] in case something happens, but everything is fine"; "I'm having some non-emergency difficulty; my expected arrival is delayed but don't send assistance unless I fail to check in again within 12 hours", "My plane is about to crash and I will be a pancake within the next 60 seconds; no point endangering rescue crews to scrape me off the mountainside but you might send someone to look for wreckage when the weather gets better", etc.