I think the govt. is genuinely concerned that we could have a serious epidemic. I'm sure you're aware that the so-called "Spanish" influenza killed more people around the world than WWI, one of the two deadliest wars in history.
For one thing, an epidemic would wreck the fragile economic recovery as people avoid any place where crowds gather -- stores, malls, theaters, etc.
The lesson of Katrina is that the govt. can't wait til the last minute. What if a serious epidemic occurred and we were unprepared?