Why practising carrier raids did not settle the Pearl Harbor threat

Why did the U.S. Navy practise carrier raids without recognising that another navy could do the same?

The explanation offered is that threat assessments and racist assumptions about Japanese capability prevented the exercises from changing expectations.

The Royal Navy was regarded chiefly as a potential threat to Atlantic bases, leaving Japan as the relevant carrier opponent in the Pacific. Racist assessments dismissed Japanese aircraft, ships and technology as copies of Western designs and denied the possibility of advanced independent tactical thinking. Officers who challenged those assumptions could be shouted down. Even after Japanese bases closed to foreign observers, some attachés continued repeating earlier claims without fresh access to the facilities they described. The exchange also qualifies this criticism: once war began in Europe, the United States sought direct combat experience, including an observer aboard Illustrious during Taranto. Whether that effort produced the necessary institutional learning is left open.