What Mike_J says and I would like to add that this may be her personality. I can relate to how she feels and I am a male. I really do not crave intimacy and the idea of it also seems bizarre to me as well. Sex for pleasure and disposable actually sounds about right for me too. I hope that is not the case for your wife, but she may be unable to engage in intimacy love simply because the concept is unknown to her as it is with me.