I otherwise liked the film, but I thought it was wrong to hide it from viewers. The bombing was the central plot point of the whole film. It would have been different if it was a new director, or surprise hit or something, but Nolan knew it would be seen by many millions of people.
It could have been shown without losing any narration context at all, in the scene where the protagonist is shown slides of the destruction scenes, and the camera only shows him looking away. The director didn't need to force the audience to look away too.