This is why a historian can read, understand (both the pros and the cons), and respect books that represent an economic history, a social history, an information history, a microhistory, and even a great-man history of a given subject without trouble.
More reason for engineers to take humanities courses!
Also, the more I learn about my heroes the more I realize that they never saw themselves as ubermensch. If anything, self doubt seems to be the common thread. I think this angle does not get enough attention.
However, I agree with you on a broader point. This is just one perspective. Here is another one: Turing the historical figure is necessarily oversold because many more people than Turing the real person contributed to his aggrandizement. Like all cultural icons, Turing the idea outlived and outshined Turing the man.
I think most of that reaction isn't coming from your narrative on history, it's from accusing other commenter's narratives of being false.