"Any monkey could have figured out the Enigma machine."
Then... Why didn't they get a monkey to do it?
Turing did something that was incredible for his time period. Sure, anyone that studies cipher technology in school now, or any hacker worth their weight in 2600 books could do it today...
But the man was working on gears, pulleys, vacuum tubes, and punch cards.
Cut him some slack.
It was a massive accomplishment for the time period.