It wasn't Wonder Woman that changed. It was Diana. Diana used to be the secret identity. Now, Wonder Woman has no down time and she's lost touch with the people she was supposed to relate to. Human females. Then DC goes and double downs by trying to make her a goddess of truth. The New 52 as I understand, has them Tripling down with having Diana directly related to Zeus.

When Marston first created Wonder Woman she was supposed to be a symbol of what women could become. That symbolism is completely gone in the new 52. About the only thing today's Wonder Woman has in common with human females is that she looks good in a bikini.