And the Exorcist merely used catholics as props in the framework of the story.
If you look at the "Devil" movies like "Rosemary's Baby", "Exorcist", "Devil's Advocate", "Damien", or any of the Grade-B ones on the 70's one thing strikes you about them. God is completely and totally out to lunch. He is no help at all. The humans are completely on their own. In fact, religion is reduced to sorcery with crosses and holy water as magical talismans and prayer as spells.
But let's add to this list of Catholic inspired movies. What about the Irwin Allen disaster movies ? Where the prophet prophesies doom and calls upon the people to follow him to salvation and they angrily refuse and immediately thereafter are striken dead for their sin ? Like the people in the ballroom of the Poseidon who angrily refused to follow Gene Hackman because "help is on the way". And drowned like rats in a rain barrel minutes afterward.