Luther was essentially a historical accident, a solid data point for the Spencerian school of thought. So at least the author gets that right. But god, when will psychoanalysis finally stop ruining academia? It's been a hundred fucking years.
I didn't read your text before I read the article. I was just about to write essentially the same thing. The overanalysis reminds me of Amy Tan's book "The Joy Luck Club". It was so overanalyzed that Amy Tan herself made the comment that it was just a book about some of her memories that resonated with a lot of people at the time. It wasn't some great historical and social commentary that it was made out to be. I think Luther was the same. He was just a guy who got fed up with the Catholic church at a time when that resonated with a lot of people. The reason it's hard to cast him as a hero was because he wasn't. His contradictions and double standards showed that. All of this historical backtracking isn't really about the guy. It's more about people trying to create an icon.
The hagiography of Luther has always been more about demonizing Catholicism than praising the man himself. Interestingly Jacques Barzun has written that posting theses on a door is the equivalent, in 2016, of submitting a paper for peer review -- and nothing more than that.