What's the Point of Watching Watchmen?

For the last week, I've been trying to figure out what issue I had with the movie Watchmen. This is a movie based on arguably the greatest of comic books. The story is one of the deepest, most layered pieces of fiction ever to grace sequential pages of art. And on the surface, Watchmen lives up to the hype. The movie is basically the comic put into motion form. On a visual level, the movie lives up to every standard that could possibly be put down. Many of the scenes are literally ripped from the pages, bringing the imagery and parallels straight to the big screen.
But something isn't right about the movie. At first, I blamed it on some of the minor issues: the cheesy soundtrack, the lousy transitions between scenes, or the awful acting of Matthew Goode (Ozymandias). However, as I was running today, listening to Alone by Heart, I realized just what was missing. It was missing heart.
My real issue with Watchmen is that I found myself not caring about any of the characters. There's no true emotion involved and it's next to impossible to care about any of the characters. Dr. Manhattan sounds depressed throughout the entire movie, Silk Spectre either pouts, wistfully soliloquizes, or runs around half naked (or naked), and Rohrshach is...well, he's Rohrshach. The Comedian is a murderous sociopath who's almost impossible to empathize with. The only character who's relatable is Nite-Owl, which provides the only character interactions that are remotely enjoyable.
I understand that the point of the movie is to portray superheroes as imperfect and flawed, but Watchmen the comic manage to do this and make you care about the characters. You care that Dr. Manhattan is detached from humanity, you care that Silk Spectre has become bitter living in the role that her mother groomed her for since early childhood, and you care that Rohrshach is...well, Rohrshach. Somehow, Zach Snyder managed to miss the entire emotional part of the story, the part that makes you care that the world is on the brink of nuclear armageddon. You don't care that someone's killing off superheroes. Hell, you kind of hope that they manage to do it in under two and half hours, just so you can escape the theatre a little earlier.
The sad thing is that there are far lesser movies that get its viewers emotionally invested in its characters. The interpretive dance that was Ang Lee's Incredible Hulk at least made you feel sorry for Eric Bana (if only for the fact that his name was attached to the movie). Horror movies make you hope that someone get's out of the haunted amusement park alive, or at least doesn't die a virgin. Hell, even The Notebook made you happy that the two old people finally died at the end.
I don't mean to bash on Watchmen. It probably is the greatest comic book of all time. I'm glad they made it, if only to bring a lighter, emotionless version to the screen. Now, when the inevitable remake comes along, let's hope that they make it with a little less "cool, slow-motion badassness" and a little more "gives a crap about what happens".