No riots in America? A sample over 200+ years, in no particular order:
Cincinnati, 1855
The Battle in Seattle
Days of Rage
1742 Election Riot in Philadelphia
1979 White Night Riot
We're perfectly capable of blowing up. The difference is, we tend to come back together again.
On 9-11, it would have been perfectly logical to think that New Yorkers would have taken advantage of the chaos of that morning, but by and large, they didn't.
The OP takes a rather dim view of us, for one who claims to speak for us. I've seen more of my neighbors helping each other during community crises than exploiting each other.