I feel like the issue of the lack of categories is very damaging to the kindle. I've decided to start an email campaign to the Kindle Tech Support in order to make this issue heard. Send an email to them explaining what you want and why it's good for amazon (happy customers, better than the Nook, etc). If enough people do this, they will respond.
https://www.amazon.com/gp/help/conta...e_id=200212360