Worse than that - KM officers complained that all naval radio transmissions were to be limited to 3 character messages as per prewar guidelines, but Donitz Wolf Pact tactics demanded constant communications of lengths far beyond 3 characters .RN studies showed sometimes these transmissions numbered over 100 per hour per boat. Why that persisted is beyond me. Furbringer [Donitz's colleague] sited this as main prewar criticism of Donitz Wolf Pact tactics. Furbringer recommended a multi dimensional attack on convoys to overwhelm the defences, with LW air attacks and surface raiders. If the LW component was just a fleet of long range MPA [ even CONDOR], they could broadcast convoy location thus eliminating the need for hundreds of U-Boat transmissions per attack.
Really- Donitz didn't want to command the U-Boat fleet at war, but Raeder seems to have cornered him into it . Perhaps if Donitz leveraged Dr Walther's "fish boat" U-Boat development , while Furbringer orchestrated the U-Boat war , they could have had the best of both worlds. Furbringer lead the TYPE-VII U-Boat development in the 1930s and trained most of their prewar crews, and himself championed a number of technologies, like rocket torpedo and sonar masking materials.
They why is easy. It is a combination of human males desire to over control combined with how it often takes years of negative feedback to learn combine with preformed ideas. You could just as easily ask why the British were so slow in moving planes from bomber command to ASW duties. Same answer. Or a hundred other changes.
And this is why is is so easy to boost anyone performance in almost any war. To move up some new tactic or improvement a few years, one has to just have someone learn the 10th time he could have, not the 30th time as OTL.
Or you can just get lucky. And to give a relevant example, in WW1, the Germans just lucked out in having U-boats able to do merchant warfare. The doctrine of the day was that U-boats were "daytime torpedo boats", and to meet this requirement only need 250 miles range and almost no speed. Some thought you needed a hundred mile range. There were discussions of fleet submarines to fight with fleets, but no one had the solution of range, speed, and other characteristics needed. The most popular idea was submarine carriers. Surface ships that had the speed and range to keep up with the fleet, with say 8 submarines that could be quickly lowered to the water to fight as the mother ship ran behind the friendly fleet. But there was a problem with the daytime torpedo boats. They were using lighter fuels in the range of kerosene to gasoline. And these fuels have fumes, and these ships tended to be death traps. So they fixed the problem by putting in diesel engines cause diesel does not go boom as easily as gasoline. And diesel gives you longer range. It appears to be an accident that the Imperial Germans had the ship they needed.
So what we often miss in these threads is we get too tied up to individuals and POD. Yes, in a ATL where I am improving Germany in WW2 and I decide to keep these two officers, then yes this discussion is highly relevant. But in a world of 'all possible POD', it is really quite simplist to move German naval doctrine 1943 to 1939. Or parts of it. It just involves a few people making different decisions, a few people promoted in a different order, or just luck. Luck is really huge in all wars. The hard part is changing hard physical constraints such as ship yards. Or developing entirely new doctrines never used IOTL or from decades in the future.