what is the point of this kind of Rarity?
Rarity in holders is the exact opposite of what you want in a PoW currency system, or really any currency system for that matter. You need the brain of a monkey to think this is a good idea.
This isn't exactly a conventional PoW system. Did you even read the OP at all or anything on the proof of rarity (POR) protocol? I didn't think so. This is an investment coin which if you actually read the OP would see why it's so brilliant.