Why? If anything, that backs me up. Jesus became a flesh-and-bones man, meaning that He wasn't one before. You really think that God is an old man with a long beard? God *is*. That's it. He breathed life into us, giving us a soul--His likeness.
Again, you can't forget the history--this was being written to appeal to pagans and polytheists. Writing it in such a way is appealing, as it makes God accessible and personal, rather than some impersonal Sun god who does what he wants regardless of its effect on humanity. Being created in the image of God is a powerful way to show that God wants us with Him, that He loves us, rather than God just being an uncaring, impersonal god (or gods) like the people of the age were used to.