These attitudes are not merely annoying or even contemptible. They are outright dangerous and nothing short of enablement.
All the recommendations upthread to turn the other way, to maintain a culture of silence, to pretend you don't know what even he knows you know, to privilege being nice and polite over uncompromisingly protecting our children, are the reason these men get away with their actions.
This thread right here is a chilling reminder of how and why this culture of enablement exists. It's full of exhortations to maintain that silence; to pretend that this doesn't happen in the face of unassailable evidence to the contrary - he's convicted, what more do you need? - all are in-your-face examples of the kind of social attitude that actively aids these men in doing what they do. There are none so blind as those who don't wish to see this particular issue.
No one is suggesting outing him, or vigilantism, or behaving in the usual ways that drive these men underground and make them even more dangerous, as warned against by all the child protection charities. But that coin has a flipside. Silence, pretending it isn't happening, deluding yourself that close supervision is all that's needed to protect your kid, failure to recognise how devious and good at playing the long game these men are: all are equally dangerous. And however well-meaning your motives, this enables abuse.
If you are posting upthread in this vein, you are contributing to this problem.