Jack Reacher is a 6'5" tall, muscular, stony-faced semi-sociopath.
Tom Cruise is a 5'7" (in is platform shoes), pretty boy.
If you've never read the books, you might enjoy the film. But if you're a Lee Child fan, you're going to spend most of your time cursing him for selling out and thinking about what might have been. It's like watching a Chihuahua yapping that he's really a Doberman.