Other reasons to not wipe
I think that a lot of people make the assumption that when they take a non-working (or not working very well) device to a retailer or warranty repair center, that the repair center will fix it and return it to them. They would not see any reason to wipe the device as they think it will be fixed and they will get the same one back. For laptops, that may be generally true, but for tablets and phones, that may not be the case, i.e., the device may be replaced with another new or refurbished device. People also don't understand that the repair people may be able to (and want to) look at their private data.
They may also not understand how to do a backup of a tablet or phone (or even the need to), so if they wipe those, they would lose all of their data, so they wouldn't want to wipe them to begin with.
