<human>: Condense the text into a few key points

I mean this for both online and the real world. Every day I see people being pessimistic and cynical to the world around them. Even if it's played for humour, the majority of people I see go for the pessimistic outlook and say overly cynical things, rather then find something good, or optimistic to focus on.
I'm just wondering if theres a cultural reason, or if it's just the way the majority of people are fine-tuned... Hell, I've seen cancer patients on their last legs more hopeful and full of life then those with a clean bill of health and everything they could ever want.  
  
I personally try to find the good aspect in any situation I'm in, I'm alive in a first world country, I have a decent job I like, someone who loves me and a fun social life. But others with the same style of life would rather complain about it (I'm talking broad strokes here, I can't believe that everyone who bitches about their life is really leading a terrible life filled with abuse and hatred, the occasional person yeah, but not everyone), it just feels like people need to complain about something rather then see the good they have.  
  
As for the online community, I know about the Anonymity factor and the fact that you can say pretty much anything without repercussions... but why would you want to? Why belittle someone, when you don't need to? Why look down on a persons accomplishments, rather then celebrate them or your own? Why be a dick to a stranger when you wouldn't anywhere else?  
  
I look around at everything I have and am content and happy, I see others with the same and they seem miserable... and I don't know why.
<bot>: Why are people miserable when they shouldn't be? (I mean the ones without any social issues, abuse issues, or physical/mental/emotional problems that would warrant a sad outlook)