The fiction can the plot, not the physics. And you'll find there's plenty of hard sci-fi novels out there. Some of those novels even get made to movies, like I Robot. Unfortunately it often gets heavily watered down.

The problem with movies is the cost of production is much higher than publishing a book. So movies have to appeal to a greater audience in order recoup their costs. And that usually means taking the "hard" out of "hard sci-fi".