I'm going to summarise the "people suck" matter in a sentence: 20% of the people cause 80% of the trouble. Most people are... neutral. Most of us are pretty selfish, even those of us who profess to be philanthropic mostly look out for our own lives first and others second. But we also follow social conventions; we tend to avoid wilfully causing harm to each other and respect each others rights to make their own ways through life without being harassed for it because it allows society to function; imagine if everyone was like the guys who threw that teenager off that building? How long do you think we'd have lasted as a species? The problem is is that this instinctively neutral, half-isolationist mind-set that humans have (and in my experience, we're not as social as we make out to be.) doesn't make for good teamwork. So the 20% of people who don't follow the rules, including the tiny minority of those who do things like the above listed, aren't stopped because the 80% of people who do respect the rights of others don't work together to stop them.
Think about it. That kid being bullied despite being completely harmless, if a bit of a social recluse. (something I can identify with.) The bullies? Probably a minority of the population. The normal schoolchildren? Probably over 80% of them were just trying to get on with their lives with no malicious intent. (and thats a bad school, what schools have more than 20% of the kids actively bullying?) So what should've happened is that the heavily outnumbered bullies should've got what was coming to them in some form or another, if the rest of the population had worked against them. But instead they just stood by and let it happen, even though its clear people knew what was going on.
The point of the above paragraph is to illustrate that people aren't inherently evil. A small minority of people are actively malevolent towards others. Its peoples neutrality and unwillingness to immediately come to the aid of other humans because it "doesn't concern them", that inner selfishness, that allows bad people to get away with what they do.
That said, we aren't all nasty or apathetic. Many people are instinctive do-gooders. But not enough of us, and we don't seem to work together as well as the bad guys... and the good people often get hit with a wall of apathy when they do want to get something done about a bad situation.
