You're misreading these people. They only exhibit 'bravery' when facing safe targets. Like well behaved, law abiding citizens, who are moral and civilized. They exhibit no such 'bravery' in the face of people who will kill them without flinching. In fact, they back down to them in innumerable ways.
If they do anything to break the social compact with us, or destroy the thin veneer of civility that exists between us, they'll suddenly be facing a more determined and violent foe than they can imagine.
The brighter among them know this. It's why they've so diligently attempted to slowly disarm us. As long as the people have the capability to return fire, they'll never do a bloody thing.
I agree, but as someone pointed out, they’ll try whatever they think will work.