Jawa Ex Machina
Veteran
Because the character you see on screen is not the character you saw on screen the last time and it's not the character you read in the comic book.Exactly, why oh why do they insist on re-telling the origin story of characters that pretty much everyone knows.
It's an adapted version of the character and with the origin story you set up the rules for the newly adapted version.
For instance, without a new Spider-man origin story, if they choose to abandon the organic webslingers and don't do an origin story, the film will suddenly not make any sense to millions of visitors and they won't like it.
Also, these movies are aimed at little kids, and a lot of them might not be old enough to have seen Raimi's spider-man.
THE INCREDIBLE HULK worked because they had a short origin montage during the opening credits and because it could be seen as a sequel to either the TV-show or the Ang Lee movie.
As for Green Lantern, nobody knows who that is.