Why Her Is Bad
It's not that Joaquin Phoenix is a bad actor. He's a terrific actor. He's just not an actor who connects emotionally with the audience very much. And when a movie revolves around endless close-ups of its star murmuring monotonal sweet nothings into a microphone, the guy has got to connect. Scarlett Johansson — who plays the operating system — pulls it off and she's not even physically onscreen. But audience connection is not in Phoenix's repertoire. I'm not even sure he cares about it.
For comparison, take a look at Oblivion. Not a great film, but entertaining. And in its first half hour, Tom Cruise basically delivers a master class on what it means to carry a movie. There's a guy who knows how to make an audience identify with and like his character. It's not an accident he's a star.
Without that sort of skill from its lead actor, a film like Her is just a charmless display of intellection. Which is all right for critics, I guess, if they're not very good critics. But for humans? Pass.