There are multiple reasons for that. As of today, movies with a big ‘buzz’ have become more profitable outside the country. Movies, especially those of Disney and A-list actors have more international appeal than domestic appeal. An example would be Iron Man 3. More than half of its revenue was from international markets. This ‘globalization’ of the film industry is mainly a business tactic to earn more revenue.
In addition to this, the international market and its reviews generate hype in the country which helps in getting greater profits, if the movie is good. Another advantage of overseas release is the limiting of piracy of movies. The piracy of movies in early 2000’s had become fairly easy due to advances in camera technology and this piracy diluted international profits as movies would reach other countries before their release date.