“those convicted of a sex offense have some of the lowest recidivism rates compared to individuals convicted of a non-sex offense”
I would imagine shoplifters, burglars, and those convicted of selling, using, or possession of illegal substances or firearms just might have a higher rate of recidivism than convicted sex offenders, simply because they have more opportunities to commit their particular crime (lower incarceration rate per offense, if at all).
Part of making sure the convicted sex offenders have fewer opportunities is to notify the public of their particular crime and whereabouts, after (hopefully long) terms of incarceration have been served.
This is one group of criminals, (aside from the 18 y.o. caught with his 16-17 y.o. girlfriend and was prosecuted), who do not reform, who do not change their ways. The same sick urges that led to their first offense remain, and will likely lead to another. The first offense was too many, the second preventable and unconscionable.
They just ain't wired right, and need to be kept away from kids.
When the State won't do that directly, parents being aware of who, what they look like, and what they did, as well as where they live, is the only remaining tool for the sort of situational awareness needed to prevent harm that lasts a lifetime for some child.