Epidemics are part of the natural order, to ignore than is foolish. In the past, we could not do anything about it, now we can if we have the will and foresight.
A flu pandemic is not the end of the world, we as humanity have survived many in the past. However, it is not unreasonable to expect 10-30 million dead with a dramatic shutdown of the economy lasting 6 months. That is a huge price to pay for something we can potentially avoid.
At the risk of being called chicken little, I am a physician boarded by the American College of Preventive Medicine and I know enough to be very concerned about pandemic flu, multi drug resistant tuberculosis, resurgence of malaria, and a whole host of problems that are lurking.
The government has wasted billions of dollars on programs that have not helped us, but public hygiene (the old term) is a shining example of their success. Most of our increased life expectancy occurred before doctor had any effective medicines. It was caused by public health doctors getting to the root cause of disease and preventing it before it occurred. Safe water, insect control, sewage treatment, quarantines, etc. To walk away from that success, assuming that we are just healthier now is foolhardy.
This isn't 1919, massive populations have not just faced 5 years of severe deprivation, etc.
I teach complexity modeling for a living and I can tell you all the spreading models are utter balderdash.
Be as prepared as you like and nobody is walking away from anything. Someone is however engaging in typical irresponsible scaremongering unsupported by the slightest tincture of fact.
It is nonsense, been tried too many times, we know the drill.