Alright cool, let's start of with 3 things:
Dr. Manhattan says towards the end of the movie: I can change almost everything, but I can't change human nature...
when things are good people (not all people but most) usually screw each other (like in the business world for example) and act egoic- but when the nation\country had a tragedy (like after a war) or after the 9\11 (in America's case) people unite and try to be better people to each other.
Rorschach says in the beginning of the movie something like: The city is afraid of me, I have seen it's true ugly nature: pornography, dirty politics, hoes and more (I just don't remember it word for word)
one day they will be crying; save us but I won't...
he has seen the ugly nature of people (the matrix analogy) and he says that in the beginning...
These are just three things now your turn...
Rorschach has is own sense of justice.. He sees and acknowledges the dark side of people, but he doesn't tolerate people acting on it. He's oneof the few who have the courage to see AND acknowledge this side of human nature.
He's also been hurt deeply by this - His mother was a prostite, he didn't know his father, he was bullied - I think he had to fight this some way, he chose to fight it externally by "bringing criminals to justice".
He's the most "human" of all superheroes I know. Not even Stan Lee could create a superhero like this IMO.
Also the "love story" between Comedian and old Silk Spectre (mother of Comedian's daughter) is interesting and understandable from this point of view
Ozzymandias is interesting characeter in his own categorry aswell. He understood that society needed the new version of Matrix at the time, the illusion, or the civilisation would destroy himself in nuclear war. It is practically another dark side of human nature, to destroy and kill each other.
Watch the director's cut if you didn't, btw.