I don't care if the film is like the books or not, it's unimportant. I only care if they make a good movie.
The Bourne Supremacy and Bourne Ultimatum don't follow the books at all, and no one on message boards ever complain.
Even if you don't like Cruise as Reacher, he's not gonna play the part for 17 movies. If it's successful, there will be more movies and more actors in the role.
If it's not successful, several years down the road Rob Cohen might make a Reacher movie with Tyler Perry.