More damage is done when there are less or no deaths, because the stimulus creates the same response from the government, and the people are still put in fear.
These attacks appear to be random and in places where the government has no plan or attempt to protect the people. The US is filled with soft targets, and while we put innocent people through the rigors of boarding a plane the terrorists are not constricted by it. There is no need for them to repeat what was successful in the past. The terrorists have been proactive, while the US government has been reactive, and this is not a plan it is a knee jerk reaction.
So, these seemingly non threatening attacks still invoke the full response of the government, This costs a lot of money, and a shutdown of areas while they investigate. Trains stopped running, and all went to Penn Station. What an ingenious way for the terrorists to get more targets in a confined area.
Subway and underground rails have so many access points it is not feasible to protect.
My point is that this is like our flight or fight primitive reaction, and the more false ones the more they drain our hormones so that when the real attack occurs we are tapped out and desensitized to react properly to it.
What is interesting is the reluctance of the media and the government to call these attacks as terrorist attacks. Does it really matter when that bomb injures of kills you?
The terrorists spent little resources, and money, but it caused millions of dollars for the government to respond to them. And one thing for sure is that we don't need terrorist reinforcements from Syria where they are battle hardened and more experienced that the fledgling amateurs here.
We can't control or stop the domestic ones, do we really need the pros to be welcomed into the country?
BTW, what are the Gun Control People talking about now? Nothing!