This ending has been debated for years. It is so controversial that when the film first ran on television, stations posted warnings stating they did not consider Bickle a hero. They're right. Bickle's a whacked-out cultural icon, granted, but he's no hero. He wants to be a hero, and perhaps the final scene is Bickle at the moment of death dreaming of a happy ending. He's essentially saved the day and rescued a damsel in distress. Bickle was seriously wounded after the shootout, having been shot in the neck. So it could have been a dream sequence, though Scorsese purposefully made it too vague to be entirely sure.
It's clear Bickle wishes to be a cowboy hero in Taxi Driver, as seen by the boots he wears and the guns he straps on like an inner-city John Wayne. His famously improvised "You talkin' to me?" speech is in fact a line of dialog lifted from the classic 1953 western Shane. And the final showdown has Bickle taking on three men (outnumbered a la Cooper in High Noon) in a bloody, ferocious battle that to this day is one of the most violent scenes in history.
Bickle, adorned in Mohawk and Army jacket, fires at random. He shoots off a man's hand, is shot in the neck, stumbles upon the stairs, slips on blood and falls to the floor. The scene is a grotesque nightmare, the stock purposely faded so the blood would be dulled enough for the film to avoid an X rating. At one point, as Bickle falls to the blood-splattered tile like a stiff mannequin, Scorsese increases the speed of the film for several frames, creating a surreal, dream-like aura. It's both brilliant and profoundly disturbing. The violence is so random and sloppy one gets the feeling they are viewing an actual crime scene. There is no music, only the jagged noises of constant screaming and guns blasting within closed-in spaces. While we love the balletic violence of the final shootout in The Wild Bunch, we turn away from the gore in Taxi Driver. It's as repellant as reality.
Scorsese's masterpiece is not intended for the young or emotionally disturbed. Bickle is not a hero in a film populated by an army of non-heroes. Still, viewers just might get confused. I know Bickle is crazy, but I feel sorry for him. At times, I even identify with him. And that depresses me.