BT18 said:
They're getting older because they have to due to the actors aging, not because it's helpful for a franchise adapting characters and 40 years of storylines which don't age much more than 10 years in that entire real world 40 year time span. And they've only scratched the surface of the Spidey mythos.
I really doubt you'd find one studio exec OR filmmaker/producer involved who wouldn't see it as obvious the advantage of a younger actor for either role when you do in fact need to recast for prolonging the franchise
You can't compare the comics to the movie franchise. They are both completely different. To begin with, they are only making a total of 6 Spider-Man films. Hence why the characters are getting older in each film. In Spider-Man, Peter Parker, was a recent high school graduate and college freshmen trying to get used to his powers. As well as obtaining some responsibility. In Spider-Man 2, he was trying to balance his everyday life (college and work) with being a superhero. So, I can imagine the rest of the series will be like this:
Spider-Man 3: Upon graduating from college, Peter is trying to make a commitment to his profession and his relationship with MJ, while being Spider-Man.
Spider-Man 4: If MJ left Peter in Spider-Man 3, then he's probably just mourning the lost of the love his life. Until Black Cat comes into the picture. He will be a lot older and wiser, so he wouldn't make the same mistakes from the past. If MJ didn't leave Peter, then they probably got married. So, this film will be Peter struggling to maintain a healthy marriage life.
Spider-Man 5: If MJ left him in SM3, then he's probably still with Black Cat or she left him (or vice versa). Aunt May is probably dead by now. Who knows! So, Spider-Man realizes that he's reaching his thirties and he's basically just Spider-Man. Peter Parker no longer has a life of his own. So, he tries to make some changes. Perhaps attempting to revive his relationship with MJ. Now, if Peter and MJ got married in SM3, then she probably leaves him because she can't handle the direction Peter's life has taken.
Spider-Man 6 (The FINAL Film): If MJ left Peter in SM3, then they probably get together in this film and the movie ends with their marriage. If Peter and MJ got married in SM3, then after leaving Peter in SM5 she decides to give him a second chance. Peter decides that while being Spider-Man is important, it is also important to be Peter Parker and have a life of his own with MJ. The film ends with MJ discovering that she's pregnant.
THE END.