As written by Brian Michael Bendis, the Ultimate universe Peter Parker was arguably the best-crafted version of Spider-Man ever created. By rooting the stories in character and ground-level plotting, Bendis gave us an instantly relatable protagonist who was a genuinely complicated human being underneath the red-and-blue spandex. Bendis made sure to flesh out all of Spidey's supporting cast, giving us three-dimensional portraits of Aunt May, J. Jonah Jameson, Mary Jane, and the rest of the crew. Because these stories obstinately took place in the real world, the violence had sting and there was a genuine shock at the loss of life (even though forced participation in crossover calamities lessened the impact of the violence in the individual stories). Point being, Peter Parker was a true hero, and a genuinely wonderful human being. He didn't deserve to die. Nor did Aunt May deserve to grief over the loss of her beloved nephew. But for some inexplicable reason, superheroes, even teenage ones, cannot be allowed to retire.USM narratives. When you spend so much energy and time into crafting a Peter Parker that captures our sympathy, you can't just casually bump him off as 'the shocking conclusion' to the latest universe-wide stunt. When you create a vividly three-dimensional portrait of a seemingly stock character like Aunt May, you cannot just arbitrarily kill off her nephew because the suits upstairs wanted something different. I'm sure Miles Morales will make a wonderful Spider-Man. Under the pen of Brian Michael Bendis, I can't see how he could not. But Peter Parker deserved more than a bullet in the ribs fired by The Punisher, followed by a final smack-down with Norman Osbourne.
In comics, and popular fiction in general, killing characters is an all-too convenient way to change a story, create momentary excitement (think 'women in refrigerator'), or signal a new narrative direction. But in the real world, people don't get killed off when they cross a certain thresh hold. They move on, they move away, they go to college, or they get different jobs. In the real world, the one Ultimate Spider-Man was supposed to take place in, heroes don't always have to die. Sometimes they do just fade away, to a life of normalcy and happiness. It was the very least Parker deserved.