The rich can afford to be careless. They can afford for their children to be careless. It's sad but true. And the system is set up to accommodate this. Think of the jerk you once worked with, the rich snot who never did her share of the work but got promoted anyway because mum is besties with a board member. The rich girls at my college were always the ones throwing their LV or MCM on the floor or their sunglasses in their bag without the case, etc.
I have to say I actually know two unrelated people I am close to who are very careful with their nice stuff. Both are self-made, if that makes any difference, so maybe growing up "normal" means they still appreciate their things and take care of them?