This is true, but I'm just looking at this on a case by case basis. They filmed 500 girls or so and how many are in the lawsuit? We can't assume all of them didn't read the paperwork, were tricked or coerced.
We don't know how you the other girls felt. A lot of victims don't join lawsuits for various reasons. Look at the initial Cosby case - 17 or so women testified against him under oath for the 1st woman's suit but only one of those actually filed her own suit. It's not an easy experience and the success rate for sex cases in court is actually pretty low.
From the articles I read it sounds like classic trafficker M.O., it's intersecting circles of coercion. You get a girl to agree early or easily, she's not going to feel coerced and is more likely to blame herself. Maybe in some cases she was already thinking of doing something like this. Maybe they even were grabbing young wannabe pros to fill out their numbers.
But other girls, who were more reluctant, they had to be pushed harder. Maybe they were lied to more or threatened more forcefully. They're the ones who are going to feel the most violated. Every girl reacts different, maybe even some of those will blame themselves, but others are willing to come forward.
When they raid a sex trafficking establishment, even the ones that have the girls on full lockdown, they rarely will have a group of girls who all have the same story. They were each brought in their own individual way.