I have a hard time explaining why there are so FEW attacks...
I think it is a tactical issue.
If you attack a lightly guarded gathering of cartoonists in Texas, you kill nobody and die. If you attack a lightly guarded gay bar in Florida, you can kill 50, wound 53, and then die.
One would be viewed as a success; the other as failure.
Each individual actor is trying to choose circumstances that maximize the damage to the enemy. They don't want to end up like those robbers who chose the wrong McDonald's to rob in France. The one with eleven armed special forces having lunch.