Desktops aren't worth very much anyway by the time most folks are ready to upgrade. You have a point as to laptops.
The poster asked about the best way to delete their personal files. Your opinion is to remove parts which someone else would have to replace before they could use it, and don't worry if that means they cannot sell it or another person can't use it that way because it is not worth much anyway. Okay. It's not mine, that's all.