From how he's talking, he seems to be your average "righteous" Christian who thinks that your way of thinking isn't right simply because he doesn't think so...quite honestly, he seems to be just as bad as he's making you out to be. Not to say all Christians are bad, but the "righteous" ones are the ones that piss me off.
I think the world is "rotten," in a manner of speaking too - but only really because it's definitely not perfect and there are many, many problems that probably will never be solved. Humans didn't evolve to be perfect in today's society, they evolved to be perfect (more or less) in old hunter-gatherer society, back when we had to be more aggressive and warlike. It's a very Christian-like ideal that the world is "perfect" and only the people who go against the grain are the ones who are causing the problems...of course, people going against the grain can cause problems, but people following the masses can be just as problematic in the long run, depending on where the "masses" are headed. Don't want to be following them if they're heading straight off a cliff, that's for sure.
I'm a pessimist by nature. Not because I want to be, it's just the way I am. If people can't accept that, screw them. Seems like you're just the same way...nothing can truly change who you are, no matter how much you would like it to be.
Doesn't mean that everyone who thinks differently from you is wrong though. Not to mention that it's pretty much human nature for young people to be rebellious. Not all are, but you'd be pretty hard pressed to find anyone who didn't have a rebellious stage...just look at that riot in Vancouver, it's not like all of them were 15-year-olds or anything. (Of course I'm not defending them, screw them...)