There’s something about a Reacher novel. That guy walking across America, hitching, catching busses, drinking coffee in diners, never washing his clothes, just buying new ones, encountering small towns run by bad men, incompetent cops and over-confident tough guys. He goes into these mean towns and isn’t himself mean. He uses his fists mostly, and elbows, and his simple moral code, but he’ll pick up a gun if he needs it. He’s definitely not Tom Cruise. He’s a young Clint Eastwood, or maybe Robert Mitchum. Who is he these days? I’m not sure Hollywood actually produces men like that any more. Maybe Matthew McConaughey, if he dialled it down quite a lot.
I read somewhere that Lee Child basically starts a story and follows his nose, and sometimes it shows. The books can meander. I read one where there was barely a fight in it and the story wandered around a bit aimlessly till it ended. Not very satisfying. That gruff, matter-of-fact style can suddenly look a bit exposed and ordinary if nothing much is happening. If the momentum of the plot sags, then it can get boring. But mostly they work. Take a clearly defined character, aim him at trouble, see what happens.
Genre is of course fluid, not clearly defined, but with these books you know exactly where you are. No character development, no big themes, nothing interesting going on with the language. Just Jack Reacher, doing his thing.