The crew accept the chance that they could catch nothing and get no money. They usually end up getting the qualified crew cheapest that way.
The processors know they will have a certain amount of work to do based on the set quota and set price for the ccrab. They hire unskilled mexicans cheap.
The fishermen & processors are 2 completely separte business entities.
Don't forget to add that those Alaskan Crabbers are working in the most dangerous of industries. Many deaths each year. That tends to drive up the wages.