His official preference of the characters? Just because he is head of Marvel it doesn't mean he has to like every character. Just to summarize it to you better Eternals have the weight of the worlds in their shoulders since they are immortal and nigh-invulnerable. This is a vital difference compared to Inhumans who are too similar to X-men. Eternals always battled with identity and purpose like Wolverine due to their powers and immortality. Gaiman touched on that.