Yep, now look up the dark past of basically any large corporation that existed at that time... wild stuff.
it makes me wonder why, when we see WWII movies or documentaries, why they are doing everything analog? Typewriters, handwritten letters, when we know they had IBM computers, which were sold to the Nazis including during the war, in direct contravention of sanctions. Could it be they want to hide that unsavory bit of history
Early computers were weighty, unreliable, and insecure. We've come a long way with network management, parity checking, digital encryption, smaller machines, and input devices that don't require punch cards. Even if we thought they could have adopted widespread use of computers in the 1940s, it would be a long time until people adapted to the sudden change.
You couldn't even purchase a modem until 1958. ARPANET was the first wide area network actually put to use in 1970 connecting computers on opposite coasts of the United States after four years of development, and it largely wasn't improved upon until ARCNET in 1986.
The Nazis literally used custom made IBM punch cards to keep records of their undesirables. I know society at large was mostly unaware of computers, but did they did play a role in WWII. We see cipher devices like Enigma in historical documentaries and fiction, but we don't see the computers that calculated bomb and rocket trajectories, and least of all the Nazi's database which seems quite well buried in footnotes, though it was critical in the holocaust.
I still stand by the answer to your likely rhetorical question is that it wasn't really hidden that much it simply was utilized so little that the exact sites and personnel that used computers of the time are incredibly few in number, so while easy to document and possibly quite impactful: it also wasn't a very big part of the era as a whole.