What Japan did made no sense to our Admirals or political leaders. It was unthinkable in many ways.
Complacency is the mother of disaster, but our intel into what Japan was doing was extraordinarily weak in 1941. In hindsight there were many things we could have done to minimize the damage on December 7th and put up a better fight, but in the end it was really irrelevant. We replaced and repaired the bases and the losses in ships and planes were replaced within the years. Japan missed the most vital targets of all since the carriers were out to sea and that was their big failure.
However, too many forget that most of our navy and leaders still believed the battleship was supreme on Dec 7th.
The attack was viewed as a cowardly act by a brutal enemy and it steeled the resolve of a nation and power that few could predict.
So, in other words, losing over 2,000 of our young men worked out great for us? Glad you were never in command of anything.