They would write it if they were writing a death scene for The Lone Ranger, Roy Rogers, or Gene Autry. And before their last breath, they'd probably tell the kid to do his homework, clean his room, eat his vegetables, and maybe even remind him to wash behind his ears...
Nah. He knows there's no place for him. This is the perfect distillation of the Western myth. Pick an actor who looks nothing like the cowboy hero of the era (not tall like Wayne, Stewart, Cooper, Scott, Fonda), dress him in white buckskin so his 'goodness' is palpable, having come down from the purifying wilderness (and possibly return - alive - to it) to right the wrongs. Note that he doesn't use his gun in anger until it's absolutely necessay and note he doffs his store-bought duds (darker clothes) and returns to his shining white buckskin for the final shootout. They even flooded the area near the farm to create an Edenic pastoral home for the yeoman farmer - the man who lives with nature but has mastered it. The cattlemen are a threat to that paradise and the progress of the West. Shane' presence disrupts the family unit and gives the kid the wrong idea about violence, but his presence and actions are necessary and after he's done what he has to do, there is no need for him to be there any more (see Tom Doniphon in Liberty Valance). Either he's dead or moves on (I prefer to think he's gone to another place that needs him, myself, but dying would make sense) - the West is growing up and moving on - note the cattlemen make an early reference to getting shot of the Indians. The film cleverly mixes the Western myth with King Arthur and Christ. I know Clint ripped this off for Pale Rider, but see also T2. The hero sacrifices himself for the good of mankind (until they made a another installment...)
Shane is a great novel and gets my vote for best Western of all time. The free range ranchers (old) and farmers (new) are the West or any place really that goes through the transition from a lawless frontier to a structured organized society. Shane is the mechanism of conversion from one to the other. The old has to die for the new to emerge. Shane died. He had to.
My theory always was that Shane died, then came back as the Preacher on Pale Rider. And then the story repeated itself, with Shane's ghost getting his revenge and going back to the afterlife peacefully.
I think that Shane dies. He just didn’t want to die with the kid around and wanted to do so with dignity.
He did not die, if don’t believe me watch The Glads Key. If anyone can take that kind of whopping no .30 30 from a Winchester would kill him. The Glass Key (1942) - IMDb
Eastwood also kind of borrowed that for the film 'Grand Torino', sacrificing himself at the end for the good of the boy and his family.
Nope. Years studying film. An accesible, though simplified, essay is Robert Warshow's The Westerner. Shane ticks many of the boxes. Also, remember what Stevens had witnessed in WW2 and he was no fan of gun violence - though, of course, Shane has to use a gun to get rid of it.