I’m going to guess rent and living expenses, like for food.
Make 14k in two weeks while offshore, not have a dime to their name 2 weeks later when they're going back out.
But there were plenty of guys making 200k living paycheck to paycheck.
Those workers often have to pay out the nose just to eat ramen in plywood closets, the money doesn't go much farther than it would in a dense city.