If he has ability and is 'better than Mirallas' in attitude, he's doing a great job of not showing it. Everton fans are EASY to win over. All you have to do is put in hard work. We are forgiving to poor quality players with little talent and will forgive anyone who is not playing well but at least is trying like crazy.
So the only conclusion is that he's not trying hard enough - as others have said. I think he's the type of player who can also maybe improve by being dropped for a while, and maybe Davies will benefit from a little run with Gana - the midfield might improve