Recent events have made it abundantly clear that Marvel will never undo Spider-Man's most controversial story, and the company's reasons are quite tragic (and predictable). Spider-Man: One More Day is quite the contentious subject among fans for many reasons, and the Marvel faithful have waited years for a writer to "fix" the story, or at least allow Peter to remember his mistakes. Unfortunately, it appears that One More Day is here to stay.
In Amazing Spider-Man #74, written by Nick Spencer, fans were teased with a reversal of One More Day, only to be met with another retcon altogether. Sins Past, itself a controversial story in which Gwen Stacy had a secret affair with Norman Osborn (that even resulted in Gwen giving birth to twins!), was explained away through a combination of Harry Osborn's machinations and judicious use of cloning technology - by now the bane of Peter Parker's existence. Erasing Sins Past was a welcome development, but not the one anticipated by fans. Why is Marvel preventing Spider-Man from discovering the truth behind One More Day and his erased marriage? The answer is both simple and frustrating: the existence of Aunt May.
By now, the climax of One More Day has been etched into the memories of every Spider-Man fan: Peter accepts Mephisto's deal to save Aunt May's life in exchange for his marriage to his wife of over ten years, Mary-Jane Watson. Fans sharply criticized the story - not necessarily for Peter ending his marriage, but the magical methodology used and - perhaps most crucially - for Peter essentially sacrificing his future to save his past. Fans want Spider-Man to grow up...but growing up means leaving behind the safe and familiar world of one's childhood. Thus, in order to truly undo One More Day, Aunt May would have to die.
Marvel has killed Aunt May (twice!) before; in Amazing Spider-Man #196, she dies off-panel at a retirement home (a false alarm; her death was actually staged by Mysterio). In Amazing Spider-Man #400, Aunt May suffers a stroke; she recovers long enough to tell Peter she's always known he was Spider-Man and admits she's truly proud of her nephew before peacefully passing away in her sleep. Three years later, her death was retconned as a "genetically-altered actress" hired by the Green Goblin, and Aunt May was back on her feet once again. Marvel desperately wants to keep Aunt May alive because killing her removes one more person for Peter to worry about in his life - but this means Peter will always have one foot stuck firmly in his past and can never truly move forward.
If Marvel truly wants to undo the contentious One More Day, Aunt May must be allowed to pass on - and Peter would have to make that decision by himself. Unfortunately, Marvel has retconned every instance of Aunt May's death in the past, and so the character appears as invincible and immortal as the Incredible Hulk. A proper retcon of One More Day could be Spider-Man's finest hour - but only if Marvel allows Peter to make the opposite choice, and sacrifice his past to save his future.