The movies are one of the great American art forms. It is also affordable and within reach for people. Going to a movie can be more affordable than going to a sports game. Some people have a favorite director, actor, or actress that they like to follow.
Certain movies are recognized by industry voters as the year's best at awards ceremonies like The Oscars or the Golden Globes for example. You can bet on just about anything nowadays. It is no surprise that you can bet on who you think will win certain awards.