I wish Sandman being Uncle Ben's killer was just a stupid retcon, to me it even ruined the origin from the original movie. His origin is now a complete joke, and so is Spider-Man himself as a hero, for letting someone associated with Ben's death go scout free without a fight. The origin, Spider-Man as a character and the motif "With Great Power..." was ruined. That calls for a major reboot starting from point A.
Plus, people would have continued to call this movie a vague Spider-Man 4 film (like they did with Superman Returns). I love the origin being included, starting it over, so there's nothing anyone can say about this NOT being its own movie.