I think Margaret Wente nails this one right on the head.
The media-overexposure of H1N1 is dangerous in its own way as people are now realizing. Part of the problem is that people in the media and government seem to have forgotten a fundamental human nature, the nature to be suspicious.
If a vendor is trying desperately to sell you something that you are hesitant to buy, are you more or less likely to dig in your heels as they push you harder to buy it? For me, I'd be less likely to buy it because I'd suspect that there is a reason they are so desperate to sell me it. Poor quality, price is too high, ancient curse, I'm not sure, but if they're so desperate to get rid of it there must be a reason and its probably not to my benefit.
People are rational beings, not irrational crazies as some would like to believe. We were told months ago that the H1N1 was a 'pandemic' and were warned that 'millions could die'. Media kept a running tally of the sick and dying. Internet sites plotted the cases on fancy maps, showing the ever expanding spread of the virus. Health groups were feverishly putting out new information every day. People watched with fear and trepidation as H1N1 reached Canada and... nothing really happened.
Some people got sick. Some people died. As Wente points out, somewhere between 700 and 1400 people die from the flu every day around the world. In comparison, only 5000 people have died from H1N1 worldwide.
People aren't idiots, they see that their friends and family get sick with H1N1 and recover. Just like they do every year when they catch the flu. The few cases that do die are few and far between. So more and more they come to believe that the government and media are exaggerating the danger and believe less and less what they say about it.
Pushing harder only causes these people to dig in their heels and take positions that typically would be untenable.
The real tragedy of all this is when a real serious pandemic strikes, people may have become so cynical about the government and media that they won't believe them at all.
UPDATE: Just noticed Thomas Walkom's article saying something similar.