Why don't you critique the German ordnance dept for some of their less than steller designs, like the 37mm HE round, the provision of a tear gas pellet in the base of the 7.92 Anti-tank rifle bullet and others.
Because these failings, if you really think so (what was problem with 37mm HE round?) were insignicant compared to the importance of the defective 76mm AP and HE shells. Really, how one can say the importance of a 5 rounds of special (perhaps somewhat naive designed) rifle ammo issued to German infantry, that would be used against occasional armored cars etc. equals the importance that US Tank Destroyers simply couldnt do their job proper against common enemy heavy tanks (Panther, Tiger)...?
Frankly only German ordonance that does not make much sense is the 12.8 cm AT gun - when they had excellent PaK 43 already, 12.8 was a not very usable, and poinltess overkill..
I agree that US ordonance was generally good. Say 105mm infantry howitzer, 60mm mortar was excellent. Other systems, like adoption of the old 75mm French guns, WW1 BARs and Browning MGs were typically mediocre, but at least worked enough well. But the 76 mm was high profile mistake.