Spying on military communications during active wartime is part of the game of war and is acceptable. Spying on the general public en masse is not.

That's not what the comment I responded to claimed.

They were not spying on people as far as I know.

Huh? The whole facility, and the brilliant minds working there, existed entirely to enable the successful decryption of Axis transmissions. If that's not "spying", I don't know what is.