If you are more open than a step it's usually because of a blown coverage or bad technique by a CB or excellent technique from a WR. Smith is too raw to be expected to being embarrassing people with technique at this point. Maybe when he becomes a more polished receiver and expands his route tree we can expect him to blow people away. But for now Fitz is going to have to do his job and make better throws when Devin (or anyone else) gets a step.