I think PPs are concerned about what happens if / when this individual is freed from prison.
He has a number of previous convictions, has previously gone through prison, ‘rehabilitation’ and probation, and still went on to commit sexual violent crimes. That leads us to conclude that the justice and rehabilitation service did not work, it did not lead to changed behaviour and more women were horrifically harmed as a result.
Many will reasonable conclude that this offender, this violent rapist is likely to continue to do harm, putting women continually at risk.
Now, for UK born offenders, the system or probation service is the only safeguard against that risk once offenders are freed, and we all know that often fails. But in this case, yes, down to a technicality of birth, there is another route of action available to the Gvt to protect women from this individual, and one which is more likely to be successful than rehabilitation and probation which has already shown to not work for this individual.