Xenforo Media Gallery add-on

My question is: Why is the Media Gallery an add-on for $15?

Shouldn't this be integrated into the forum software already? I'm looking to purchase a license of xenforo but don't want to have to purchase an add-on just to use a media gallery. Maybe I'm confused on what exactly this mod is bringing to the table.
XenForo is more or less a modular system and the base system doesn't include the Media Gallery.

The Media Gallery use to be a user contributed add-on by Chris. When he went to work for XenForo the Media Gallery remained an add-on to the base system, but is now offered directly by XenForo itself, not as a 3rd party add-on.

If you want to see the Media Gallery in action, take a look at triumphtalk.com. He uses it.
The reason why the base system doesn't include the Media Gallery is it would be unfair to sites like mine where I don't need the gallery. So, why should I pay for it if I don't use it? ;)
Right, so what I'm asking is what exactly does it provide that a base system doesn't already? I mean, I can add images here. What else does the gallery do?
You can add images to posts anywhere on the site.

In short, the Media Gallery gives users their own media/photo albums.

DirtRider might be able to explain it better since he uses it on his site. But I don't think he'll be back online until late tonight or early tomorrrow since he's on the other side of the world.
The members really like being able to have their own galleries and it makes it easy for them to manage all their images. It also has an option that will allow you to insert an image directly from one you already have when creating a new post.

See the icon circled in orange and this is what it will do