Luther sowed the seeds of this abominable theology when he rejected the authority of sacred Tradition when it came to Biblical interpretation.
Within 150 years, you had the rise of Pietism, and the Lutheran Confessions became increasingly disregarded until the 19th century when people like CFW Walther fled to America.
We are seeing the fruits of Pietism in stark colors.
I hear what you’re saying. When the Word of God is in the hands of the people they can come up with all kinds of uninformed interpretations.
But then, so can the academic or ecclesiastical “authorities”. The “sacred tradition” would have killed Galileo for believing a heliocentric solar system. Men make mistakes; happens to all of us. We have only to look at the academic elites today to see that anything man does is fallible.
That’s why it’s so critical that our salvation not depend on mere men. That’s why I’m so thankful that God gave His Word - and that He gave so many ways to know that it’s really from Him, ways to check its authenticity, reliability, and accuracy - both before Jesus’ nativity and after. We aren’t asked to have blind faith; we are given lots of evidence that what was spoken in the Bible is true.
Luther’s premise was that Scripture itself has authority above any mortal man. One of the hermeneutical principles he adhered to was that of Scripture interpreting Scripture. God doesn’t contradict Himself, so if we want to understand what He’s saying - and what He’s NOT saying - we have to look at other parts of Scripture. That keeps any person from being able to come up with their own meanings and claim that it is God’s meaning.
If the ELCA used that and other hermeneutical principles taught by Luther they would not be preaching theology that is contrary to Scripture and to the Lutheran confessions.
The ELCA was able to go so badly astray not because they let somebody besides the Pope interpret Scripture, but because they gave up on the belief that the Bible is the Word of God - all of it - and instead claim that the Bible CONTAINS the Word of God mixed in with a bunch of other junk that they can reject as they see fit. And that’s what they’ve been doing ever since: rejecting whichever parts of the Bible they don’t like. They are making their OWN “traditions” rather than the old “traditions”. The major difference between the earlier “traditions” and these newly-invented “traditions” is their age. Both come from the mind of man, not the revealed Word of God Himself.
So the problem comes in when there is some authority higher than the Bible - whether it is the Pope, the ELCA higher-criticism scholar, Martin Luther, or you or me. The people who have the words of Jesus are the people who were with Jesus when He said them. That’s what we need to hold onto.