Question

Why was a pirate crew sometimes called a “motley crew?” (Motley Crew is also the name of a rock band.)

Answer 1

The term "motley crew" is actually used in fictional material, such as books or films.

Step-by-step explanation:

Because members of Jack Sparrow's crew aboard the Black Pearl, in the films they were referred to as the "Motley Crew", so fans assumed that was the name of their group.

Answer 2

A motley crew is a gathered group of people of various backgrounds, appearance, character, etc.