I agree we are getting more idiots in our presence each generation that goes by. It's got a lot to do with people not gettin' their asses whipped when they were kids and our justice system slappin' 'em on the rest when they grow up.
There's definitely the argument of more densely populated cities and a larger populus overall. That alone means more violence and crime.
I still think for the old timers saying "What's this world coming to" it's just a matter of watching too much crap on TV IMHO. You can't watch the news AT ALL without mention of some wacko going on a shooting spree... and usually it's 3,000 miles away from where you live and rarely affects any of us viewers' lives...aside from the fact that it's makin' us paranoid as hell!