Those who deny inerrancy end up replacing the authority of the Bible with their own authority because they get to determine which parts of the Bible are divinely inspired and which are not. The process is almost entirely subjective.

The tendency is to deny the inspiration of any part of Scripture that does not line up with what they think is true. When the Bible’s sexual ethics conflict with their sexual ethic, it is because those texts reflect man’s opinion rather than God’s. When the Bible’s teaching seems to conflict with the current scientific consensus, it is because those teachings are not inspired. When the Bible portrays God doing something that conflicts with their understanding of God, those passages must reflect man’s ideas rather than God’s. In the end, the Bible (and Christianity) is remade into their own image. When God just so happens to endorse everything you already believe, you’ve probably got the wrong God.