Mostly you are an idiot.
I agree with your first sentence. For better or worse, most of the time we are the product of our parents ability and willingness to raise us. Unfortunately willingness and ability do not always go together.
None of us know why this kid is on his own or where his parents are at and you're a dick for making stupid assumptions about people and their circumstances. Despite the assumption that people on welfare (not wellfair) are lazy and don't want to work, most people who live in low income housing or are on social assistance are for a reason. Poverty is a HUGE and COMPLEX barrier that most people aren't able to overcome. More often than not mental health is an issue. Throw some addiction issues, history of family violence and abuse (along with the unresolved emotional trauma that comes along with that), racial barriers, single parenthood, etc. (I could go on and on with this list) and see where you end up.
I think it's sad and unsettling that someone is walking around taking a video and laughing at this kid. Even more so if it's someone who knows him (I'm pretty sure it's not a parent).