That Hitchcock wanted to fuck Grace Kelly is demonstrable fact, but I don't agree that it's the whole point of Rear Window.
As for what you missed, Andy, I might mention off the top of my head: themes of impotence, sadism, masochism, the male gaze. One of the greatest pieces of set design of the studio era. Hitchcock's agonizing awareness not only of his desire to fuck Grace Kelly but of his Catholic guilt over it. Grace Kelly's wardrobe. Hitchcock's canny implication of the audience in the thrill of cinematic voyeurism. And the fact that despite his reputation as the Master of Suspense, Hitchcock's films are almost never mere thrill machines, but stories about conflicted sexual relationships, this case being (along with Vertigo, Psycho, and Notorious) among the most twisted. Consider how Stewart's character fastens on the possible murder across his courtyard as a rationale for his fear of committing to a relationship with Kelly's. And how he finally gets turned on by her only when she's in mortal danger. Start there. If considerations like this really don't move you at all, I'll stand by my initial impression that it's responses like yours that typify the doom of cinema.