Gavra, it is much easier to have a list of acceptable hechsherim than to figure out which books are okay. Also, the yetzer hora for non kosher food is much smaller.
Education. And you can whitelist and/or screen if you want.
Syag, it’s okay to swim with a lifeguard, and okay to walk into a library if the parent knows what’s okay and is supervising. I’m not sure that we’re disagreeing.
Not exactly true. Even with a life guard, you need to pass a test to go into the deep water, and (in some camps) have a “buddy”.
Once again, education.