Because the way the community arrives at meta knowledge and its geographical distribution is very informal. There are quite a few false metas out there, or the commonly understood range of the meta is inaccurate.

What needs to happen is automated image recognition and mapping of the metas. I started building an open source tool that allows for people to do this manually, but it's quite a difficult project to do myself and I'm not pursuing it anymore. But I would like to see a less manual process emerge.