MasterOfAll

Question: This actually refers to the whole arc of Harry Osborn's role: Why did the film-makers want him to become a villain? I know they needed one for the third movie, but why make it one of Peter's closest friends? Was it an illustration of how big a difference, for good or bad, a single misinterpretation can make? A lesson in knowing how to look at a situation from someone else's perspective as well as your own? Or, was it just a really tragic way of showing that not all of Spider-Man's foes are going to be people he feels no regret over beating the pants off?