I care about characters, and I believe a characters history and their development and how that informs their personalities makes them who they are, and enriches whatever concepts or ideas you come up for with them. That is almost universally seen as an important element in writing and world-building but obviously wasn't something the New 52 was all that concerned about, at least in some respects.
I know there are some fans who care more for characters on a conceptual or potential level, but just seems surface-level rather then the real meat of the character. It's what drove the Silver Age but only really clicked with the maturity, continuity, and ongoing stories of the Bronze Age and Post-Crisis era.