If you click on the picture, you can see it's the same form-letter response I got, just to a different person with a different case number. As you can see, the case numbers are probably sequential.
I can understand the NSA's perspective. They got a flood of requests that they are probably going to deny anyway, and carefully considering each one would take months with the limited resources they have. Therefore, they sent out the quick denial.
But at the same time, this subverts the intent of FOIA: the people holding government accountable. The NSA exploits fear of terrorism and the "necessity" of secrets to hold itself above accountability. This is just another example of their malicious intent to hide from us.