The Americans were assisting the Royal Navy in their search for U-Boats while under the guise of “neutrality”; the U-Boat commanders were naturally (and justifiably) outraged by this and wanted the opportunity to fight back.
Yes, precisely.
But the German Submarine commanders erred by underestimating radar, and most particularly, the incredible productivity of American industrial might.
One of our major advantages was were producing Liberty boats faster than they could sink them.
They could not produce submarines faster than the allies could sink them, especially as we had broken their Naval code.