The resale value is secondary for me, I just don't like marks or scratches on my iPhone or iPad.
Apple make beautiful devices, I like to keep them the way they came out the box. I use a case when I take my devices outside but at home I'll take them out the case. I don't feel the need to show off my devices in public, so having them in a case is fine. I bought my devices for me to enjoy, not others. When I want to enjoy the design and feel of the device "naked" I do so at home where it's far safer and less prone to trips and falls.
I just like to keep my things in good condition, that's it.
There is that too. Personally I don't like getting scratches and dents on my devices. A case goes towards helping that doesn't happen.
