I retract the implied contradiction between checking the list and complaining about the content. That said, it probably is impossible to understand the reasons for its existence or the need to check out a neighborhood like this without growing up in a culture like that.
I have, in the past, used maps of homicides/burglaries/assault to help determine where in town I'm going to live.
That hardly seems strange in any way to me, and sexual predators is just another type of this kind of map.
For example, imagine Google Maps with overlays for different types of crime. Say I check the "Sexual Assault, Children" box and notice that the park two blocks west of the plasma bank has a much higher density of such crime than the park two blocks east. That's useful information, and you can inform your kids to be careful at the park or avoid it altogether.
What's not really useful is knowing that the dude five houses down from my potential new home purchase was convicted in 1995 for diddling his niece and for possession of kiddie porn in 2002, and was released in 2009 after 7 years in prison. It's pandering to the scare-news watching masses and causes undue harassment/problems of the man who has supposedly paid his price to society.
This society does not need a Scarlet Letter mentality.
It's quite reasonable to find value in the lists of dangerous sex offenders, while criticizing the inclusion of people for trivial offenses.
Why are you checking that database in the first place? In my world your access to this information is the reason for its right to exist in your social context. I doubt that it's possible to check these lists and criticize them at the same time. What lead you to check it out?