A disputed explanation for German cruisers' 4.1-inch guns

Did German light cruisers receive 4.1-inch guns merely to appease politicians?

Alex Clarke disputes that explanation and suggests that these were the best guns available at the time.

A viewer cites Warship 2020 for the claim that German light cruisers received 4.1-inch guns to appease politicians. Alex Clarke accepts that the claim appears in the volume but questions its explanation. His alternative is that the navy chose the best guns it could obtain at the time. The two interpretations remain unresolved.