The practice of cursing is widespread in certain cultures. It thrives on the willingness of people to attribute power to it. Someone lays a curse on a person. It's necessary that the person be aware that he has been cursed so that he will tend to attribute every thing that goes wrong in his life to the curse. His old car finally dies...it's the curse. He can no longer get to work so he is fired, it's th curse. He has no income so his wife leaves him, it's the curse. And so on.
Do you see the similarities? By attributing these murders to AQ, or AT, without any real, factual evidence that they are responsible, you are empowering them, just as the 'cursed' man empowers the concept of the curse by blaming his woes on the curse.
AQ and it's alligned terrorist are determined enough. They don't need us stoking their reputations by giving them "credit" for that which they may not be responsible for.
count me as among those hoping for the best, but preparing for the worst ...