...rather than the good in someone?

What's wrong with the people of this world? No one is worthy of praise or support? We all have to look down on each other and think the worst about people, even strangers.

Many argue saying Why should I respect you? For all I know you could be selling drugs to kids to make a little extra money or you could be a serial killer! But what would make someone come to that conclusion in the first place? Why is it so much more easier to believe those sort things about people rather than the good? Is it paranoia? Or
have we humans basically made a reputation for ourselves as being cold-blooded evil monsters?