I'd say this is accurate for me. I picked up an iPhone 7 in matte black over the weekend. I'm currently using it without a case and I have one being delivered tomorrow. But once I get my case I will go back to being less careful with it. That said, me being less careful is probably somebody's careful. I usually don't have any easily noticeable scratches (if any at all) on my devices after a year of use.I have a theory that some case users (not all, but some) become LESS careful with their devices because subconsciously they believe the case will protect the device. After all, that's why they got a case right?
I believe my theory is probable because I see more device users with cases tossing their devices around then I ever do those that do not use cases.
Again, not all case users - just some.
But Apple devices usually look amazing without cases.