But why a remake?
Because it has a built in audience. That's all Hollywood cares about anymore. Movies very rarely build on word of mouth and make money. They get pirated and put up online too quickly. Hollywood makes remakes and blockbusters and franchises because they can get the huge opening weekend and coast to a money maker. That isn't going to change any time soon, either. The sides of the piracy battle are too firmly drawn. The smart thing would be to accept that some people are just assholes who will steal your movie no matter what. Do simultaneous releases at home for smaller movies, accept that not everyone will pay for them, and take what money you can get back. People will pirate, but hopefully fewer of them, and some good movies will get a chance to be made that simply don't in the current climate.
Basically, blame a rampant sense of entitlement to all forms of media and a dinosaur distribution model that stubbornly refuses to accept it can't get unconditional surrender. That's why a remake.