They generated a lot of negative publicity when they announced the marathon would go on. I do feel sorry for the runners who had prepared for this - many of the slots are filled by lottery so you don't just sign up and go. However, their loss can't be measured against those who lost homes and are protecting their remaining business assets.
I often wonder about economic impact numbers. I don't think they take into account opportunity costs. How many people avoid spending that would have otherwise. For example, I did not eat out the week we hosted the Super Bowl because we expected every place to be crawling with people (or so we were told.)