It seemed more like he felt he was unfairly being uncredited. Which is probably why he wrote this - he now cares deeply about giving credit to the right people.
Surely the more noble cause for that would be giving more credit to others, rather than attempting to take away credit from a well known figure. This article is somewhat about the other important figures who's knowledge Turing's was built off, but its central point is that Turing gets too much credit.
I understand why he'd care about that if he'd been uncredited and watched peers be overcredited, but I'd hardly call it a noble work, even if it is understandable.
The article is called Turing oversold, and the article is all about who should be getting credit instead of Turing. This isn't "Hey, are you aware of all these people who helped develop computer science", its "Turing is overcredited, heres a list of other people to support my argument"
It seemed more like he felt he was unfairly being uncredited. Which is probably why he wrote this - he now cares deeply about giving credit to the right people.