Not every story is happy, it is reflecting on a post apocalyptic world where it portrays the brutal nature of it, you of cause have your opinion and not to buy it is also your choice but going by its sales you are in the minority as it had record sales at the time, the whole Internet outrage was the minority with the loudest voices, listening to them I was skeptical myself, having played it I then dismissed them like most have.
The main character is still very much the lead character but you kind of spoilt the game plot yourself by watching it first, experiencing it without expecting was how they intended it to be revealed, its like been told the twist to the 6th sense before you see the movie, it ruins the experience.