There is a relative importance to criminal backstories.  I'm aware that most criminals can point to a backstory that has something to do with why they are where they are in life.

The "bunk" is not to deny the criminal backstory, but the claim that  we can make a generic backstory in respect to one crime, which elevates and absolves the criminal of any moral responsibility.  

That is what these Sisters seem to be doing in respect to women who choose prostitution.  They are broadening the legal definition of "trafficked" to apply to any adult woman who choose to sell favors, equating them with women who are legally trafficked sex slaves.    I don't buy their argument.