And I am even happy as a second hand laptop buyer. The last thing I need is to buy a stolen laptop. At least here, I am still liable even if I don't know for a fact that it is stolen. In any case I don't want any part in stolen goods market.
I think, over time, laptop owners will learn to preserve their key so that they can unlock the laptop when they want to resell it and buyers will learn to check if the laptop is unlocked. What's the problem?