You realize some of it is pure and simple math, right? The death rate so far doesn't seem astronomical at all, sure. And it's mostly senior citizens. BUT...you have roughly 10%-15% of those who get this thing needing hospitalization. They aren't dying in part because they are getting proper treatment. Not a "cure", but are having their vitals monitored closely, IV's when needed, etc. What happens when this thing keeps spreading like wildfire (which it is) and the numbers of infected spike up? If a million people (keep in mind that's only 1 in roughly every 325 Americans) get this in the U.S. in a short time, that means 100,000 people AT LEAST would need hospitalization to ensure the best chance of recovery. Want to guess how many hospital beds there are in the entire country? 90,000. Now, how many are already occupied with people that have something else they are being treated for? Do you see where this is going? All of a sudden you have WAY more people that need assertive medical care than what the system can handle. That death rate you keep saying is insignificant won't be that way at all at that point.
That's why these measures are in place. Not necessarily because they think they can STOP the spread of this thing. But then NEED to slow it the fuck down, so the healthcare system doesn't get overloaded. They call it "flattening the curve".
Italy has not flattened their curve, and their hospitals are ALREADY starting feel a major strain in trying to keep up with this thing.
THAT is why all these infectious disease experts are calling for what seem like drastic measures (closing schools, etc.)