This virus has different properties from the flu. It actively destroys lung cells. It's not clear that there is long-term immunity. Concentrated exposure is very lethal; we have several members of a NJ family die after contracting the illness during a dinner party. We have only a fraction of the hospital capacity for all the coronavirus patients and this also hurts ICU patients with other diseases.
I don't think that we want this disease to embed itself in the same way as the flu currently does. We can't have this disease mutate each year like the flu and cull an additional 2% of the population annually over the current annual death rate of 0.95%. Overnight, this virus would become the leading killer--more than all other causes combined. The number of people that will die from this disease compares with major wars.
This is just the first of this type of pandemic. There were other viruses like bird flu and Zika that didn't have an impact.
This also causes society to reorganize itself to lessen the impact of future pandemics. Even without the government actions taken, the fear was already affecting travel and other industries.