One bad day you decide you’re going to commit the rest of your life to God, and reach a compromise to avoid sex forever. Another day, much, much later, you begin having urges, and they get so strong that the idea of abusing a child passes through your mind. If your initial intention of dedicating the rest of your life to God has led you to this point, wouldn’t it be just truer to your initial vocation to renounce your vows so that you can have sex with consenting adults, rather than harming a child?
Then again, the Catholic Church treats abusers better than it treats resigned priests.