I agree that we haven't had a reason for a nationwide EAS alert before, and the probability that we'll ever need one is (thankfully) quite low.

However, I come at this from a different perspective: Whatever your emergency plans are, it's very difficult to be sure they work if they aren't ever tested. In the world of IT, you need to not just backup your data but test restoring it from the backup media. You need to not just have business continuity and disaster recovery plans, you need to run test scenarios to see what needs changing. You can have the most perfect plan, processes, procedures and equipment possible, but if you don't practice the training degrades. I have customers that do full-scale backup datacenter tests quarterly.

Should we be having a nationwide EAS test every week? I would say not even every year. But testing it once every few years makes sense to me.