Gutenberg didn't invent the printing press. He invented movable type. There were printing presses in operation at the time, the big difference was the cost of what is now called typesetting.
And was it really pornography that they objected to? I though it was mostly heresy (including the risk that has come true, that God's own words would be used in bibliomancy and the subtle idolatry of literalism) and political pamphlets.