Unfortunately ‘WordPress’ has higher standards in terms of aesthetics. An approved design in other categories does not guarantee an approval under ThemeForest’s WordPress category. Your design has an interesting starting concept, but it needs significant improvements in terms of aesthetics and attention to details.
As higher quality items become available in the marketplace, approval requirements will increase to maintain appropriate marketplace quality.
While I’d be able to provide feedback as to how to get this approved, I can only do after it has crossed a certain threshold, quality wise. I’m sorry to say this isn’t there yet.