If the data was extremely confidential, yes, although very few people or even agencies can recover data that has been securely wiped, which was a suggestion from many on the thread, so it is kind of overkill for most people. Then a lot of buyers might be leering of purchasing that way, not understanding how easy it is to pick up a hard drive and install it.
Desktops aren't worth very much anyway by the time most folks are ready to upgrade. You have a point as to laptops.