why are parents so over-protective of their kids?

I am 28 year old guy with a 9 year old kid, and parents bitch about how I "neglect" my kid ever since I moved to a new neighbourhood.

I tell my son he can go wherever he wants as long as he has his cellphone and checks in once in a while, by sending a text. Most of the time he spends outside, across the street playing in the playground or playing soccer with some older kids, in the field behind the houses.

This incident happened 2 weeks ago:

>sunday morning
>let my son play outside
>30 mins later
>some fat bitch comes over to my front porch and rings the doorbell
>I answer
>"Hi, uh.. I was just wondering if you are aware that your son is across the street"
>"Uh.. yea, is there a problem?"
>"Oh no I was just assuming he went without your permission and you didn't know about it hehe"
>"oh, no it's all good. yea I let him go after breakfast, thanks though"
>"no problem, if you want I can watch him for you until you can come out"
>"nah thats okay, I am just working right now"
>"but what about your son"
>"what about him?"
>"you just let him go outside without supervision?"
>"yes, why woudn't I"
>"seems rather careless to me, what if something happens to him"
>"what do you mean?"
>"there is lots of messed up people out there if you know what I mean, someone could snatch him up"
>"highly unlikely, anyway I gotta get back to work"
>"I think you shouldn't let him do that it's dangerous"
>"thanks for your opinion, bye"