Why did the Germans think the Enigma code was unbreakable and?
That’s a really good question. I think one of the other answers mentioned “hubris”. The German leadership genuinely couldn’t countenance the possibility that the system had weaknesses. The wikipedia article on this is very good, and discusses amongst othe things the difficulty faced by the Bletchley Park Code breakers in dealing with the German Naval codes, which due to operator training were initially much more difficult to break than the Luftwaffe’s (Air Force’s) equivalent.
