I think the problem is that the �public at large� is an easy one to throw blame without recourse and that is why he focused on it. If he had said, the police, social services, local council, then perhaps he might have felt a bit exposed when they turned around and said, well hold on there now bucko, it was her decision and we did try to help her etc. If he had blamed the pimps and punters, he would not have got much pity. I suspect many men who use such services, convince themselves that the women are doing it out of choice, and would not even consider any claim of exploitation. So a shout against those would have fell on deafor unsympathetic ears.
Generally I believe there are those women who do it out of choice, and there are lots more who don�t. We have awareness programmes and undercover police operations, and legal reviews, but as for the general public (excluding the punters) I am not sure what we could really do other than try to put men off the idea (never going to happen) or reporting brothels and street walkers when we see them (if the girl seemed old enough, would that really happen? Would the public want to get involved).
So generally, he is probably feeling guilty at his own inaction, and wants to share that burden with the rest of society.