Well, if the stock market is crashing already in anticipation of such an event, imagine what will happen if the virus ends up infecting over 1 billion people -- it may... or it may not. We just don't know for sure yet. When the number of people in the U.S. reaches 10,000, or when large numbers in India are infected, then I would start to be really concerned.
I think it is logical for our reactions to reflect the seriousness of the perceived risk. Let's say that you believe there is a 50% chance of the Coronavirus going pandemic; and, given that this happens, there is about a 70% chance you will catch it; and, given that it goes pandemic and you catch it, let's suppose there is a 2% you will die in the next couple months. Then, the chance it will go pandemic, that you will catch it, and die from it soon, is around 0.7%, and if you are a male, it might be 1.4%. That's SIGNIFICANTLY higher than your chances of dying from anything else in that time; and your reaction should reflect that.
Furthermore, if you consider your chances of getting very, very sick, and having to be hospitalized for a significant amount of time with round-the-clock care -- not dying, but worrying that you could any minute; family is called in to see you one last time; relatives cry and cry -- then the probability might jump to 3% or 5%. If you include "the worst case of the flu you have ever experienced, causing you to miss a significant number of days of work and screwing up your schedule", then it might be more like 10%.
Again, I am not saying any of this WILL happen. But it could; and therefore, you should care even if you're not "about to retire".