I understand the "meta is murder" argument, and it's a tough and deadly problem. But I don't think splitting the meta into a separate site is the answer. You end up with a very strange self selection problem, where the "meta" community isn't very representative of the community at all.
Mods don't really set policy they enforce it, and most "Is this kind of question ontopic here?" style scope-adjusment can be done on meta.