The functionality of this Pencil holster is questionable, but the form is on point. Like any Apple product, it's well-constructed and clearly a lot of thought was put into the design. It comes in four colors and is made of leather. It's important to note you can't actually use the Pencil when it's in the holster: This is a protective holder, not a usable case.
The one-pencil holster is even more puzzling when you consider that Apple also released leather sleeves for the iPad Pro line that have built in Pencil holders. The only real point to a holder would be to avoid losing it -- so, then, why wouldn't you buy one that's already attached to a case? Are people really that concerned about getting scratches on their stylus? (I mean Pencil, whoops!)
While we might be scratching our heads at why a person might want a standalone pencil protector, Apple clearly thinks there's a market for it. And considering Apple spent a ton amount of time reviewing new iPad features at WWDC, it's clear they value the product and think consumers will want to protect it.