I'm also not convinced you can really blame urbanites for the fear of terrorism. Cities might be the preferred target for terrorist attacks, but at least in the USA people it's rural folks who tend to be more worried about terrorism while urbanites tend to take a more balanced view of the subject.
[Highly urban-oriented personality here, decidedly with you in general ...]
Here, a purely rationalistic and quantitative analysis might not back this up. It's not necessarily clear that there are fewer vehicle-miles travelled and fossil fuels expended in stocking every corner grocery in a dense urban metropolis vs. one 3000-mile salad backhauled to a Walmart SuperCenter to which everyone within a 10 mi radius has to drive. Pound for pound, the latter approach might actually be more cost and resource-efficient in a lot of cases.
But of course, there's more to life than robotic efficiency.
I personally think urbanization brings with it more problems that it solves. While they are more social perhaps, cities are anything but sustainable and aren't a natural way for humans to live with nature. Cities are a breeding ground for man made disaster and are IMHO one of the reason the fear of terrorism is winning out over personal freedom.