It should never be used as a reason for a lesser sentence.
And these rapists could have been lying in order to try to manipulate the jury.
That does not mean though that an adult who was abused as a child is not more likely than someone who was not to commit a crime, including a sexual one. Of course not all but it is known a proportion do.
In a sample of 2,759 CSA victims who were abused between 1964 and 1995, it was found CSA victims were almost five times more likely than the general population to be charged with any offence than their non-abused counterparts, with strongest associations found for sexual and violent offences.
https://www.aic.gov.au
PDF
Child sexual abuse and subsequent offending and victimisation
Other victims of csa will grow up to be particularly empathetic to and caring of children.
Yet others may be violent to themselves in some way through drugs, eating disorders, depression, suicide etc
What makes the difference to their outcomes, I wonder?