1) Automobiles have a vast amount of land space dedicated to them. And the land that is not physically occupied by parking lots and roads is subdivided, separated and made inaccessible[1]. And this trend is continuing[2]. It's why other large mammals (bears, moose, wolves) face significant problems in reproduction. Add to this the noise and the light pollution and even if you did not fear that your neighbor, reaching back to pass an organic fruit-leather to the fruit of his loins, would mow down your child, the available outdoors is just not what it was.
2) Paedophiles and rapists are greatly facilitated by the availability of fast, relatively anonymous, convenient transport. The same characteristics that make said automobiles attractive to terrorists (when they're not actually directly driving them into people as a weapon that no one acknowledges).
1. http://blogs.discovermagazine.com/d-brief/2016/12/19/roads-i... 2. http://science.sciencemag.org/content/358/6362/442