A problem with faiths is that the more values and doctrine you add to them, the less people can fit in the mold. That's why national faiths are so vague, so that everyone, no matter what they think, can "fit in".
This. This is what has always bothered me. Vanilla religions have the advantage, because "specialized" products, like mythologies, unique religious structures, interesting moral positions, gain nothing, yet may alienate some people. They have a hard time mobilizing passionate players, but an easy enough time surviving with members.
