You would be surprised on underground economy
@Richard
Maybe the thief that grabs your laptop has no idea whether it has any value except hardware.
But I wouldn't be too sure of the middleman who buys the laptop.
Odds are that there are quite a few of those who know enough to boot the laptop and see are there any company names or domain names visible.
After all if they manage to sell it for someone interested in ID theft of industrial espionage they get more for it.
But you are right, that any encryption makes the data worthless. Also it's a very good idea to have bios startup password. Some of them can be cracked, but that is still extra nuisance for the criminals.