Well, Rouen is presumably from Skullstone, which would help explain why he's a ghost more easily than dumb luck on Misho's part. If that's the case, Celestial Exalted are just another part of society. Solars in particular are likely viewed as backwards cousins to the Abyssals, trying to emulate their divine grace without earning the status of righteous dead first. No wonder they're Anathema!