To put it simply: society is sick. People would rather put kids on leashes, or drug their kids, so they don't have to do any parenting.
until you have a kid of your own - you have no room to speak
if anyone has kids - you would know they like to wonder off, constantly - mainly because 1) they get frustrated with staying with their parents 2) they're curious about there where abouts.
i never noticed this, until my aunt had her child (my cousin - he is now 2) and figured it out when my sister had her child (my niece - she is now 1 1/2) - they both love to wonder off, open the doors and run out of the house - we've since fixed those problems by adding screen doors and locking them
so honestly - i don't blame them - you wouldn't want your child wondering off while at the store or something, would you?