It never occurred to me that Captain Stacy's death would result in Gwen "hating" Peter and until you mentioned the similarity between Peter and Harry, I hadn't even thought of it. IMO, that would actually be a very dumb reaction because Gwen knows Peter is Spider-man and she knows that her father's job carries the reality that he may die every day he goes to work. Their relationship, I think, would just be complicated, nothing within having to do with "I hate you now because you couldn't save my dad, or I hate you now because you caused my father's death". At least in this film, Gwen lives knowing that her father might not come home and she probably knows that Peter is Spider-man in order to save lives (Uncle Ben's death should also mean something to her as the reason to why Peter is Spider-man). Also, until we actually see the movie, we don't know whether it's Peter or Gwen who initiates "I can't see you anymore". Wouldn't it be interesting if it's Peter who says it, for various reasons?