But some of the factors you list are present most every season...and these drops are enormously greater. It makes perfect sense that a high-profile military crackdown is going to keep a lot of people in their homes unless strictly necessary...and restaurant visits don't qualify as such.

Most non-chain restaurants operate on thin margins. If this trend continues in DC, it will mean a large number of failures...restaurants going out of business at an even greater rate than usual, people out of jobs, suppliers affected, etc. I'm dubious this is on the right side of the "balancing freedom with security" equation.