As I understand it, the difference from flu is that it's much, much more contagious. 10 pct hospitalized is very different if there are 100,000 cases vs 100,000,000. There are roughly a million hospital beds in the U.S., I dont know how many ventilators but a lot less. The healthcare system could be easily buried if we can't "flatten the curve". The same number of people, roughly, will get sick, just not as many at a time.
The mortality rate is around 1% which is more than 10 times than flu. The hospitalization rate is 15% and the ICU rate is much bigger than flu. If you run out of ICU room, more people will die.
We don't actually know the mortality rate. Or rather we don't know it defined in the way people care about ("what is the likelihood that I might die"). The closest data seems to be South Korea where they're doing mass testing, but even then, are they really doing scientifically valid random testing or are people still self selecting?
I've sort of swung back and forth on my concern levels about this, so I guess I understand the OP's concern but also the lack of concern in the people he talks to. I think it's a mix of things:
1. People learn about this via the media but a lot of people (more than half) deeply distrust the media. They think journalists lie all the time. Trust in media polls have been in decline for a long time, so when reporters turn up with "omg panic" type stories, people don't take it seriously anymore.
2. People have been receiving very mixed messages. It's a killer plague but it's also kinda like having a bad cold. The death rate is way higher than normal but it's 0.5% in the only country doing mass testing, which doesn't sound high. It's incredibly dangerous but it's also harmless to children and healthy adults. Thousands are dying but most of them were about to die of old age anyway. It's going to crash the economy but that's because the government is shutting everything down, not because people are actually unable to work. It's so infectious a single touch can give it to you, but it also requires standing around someone infected for 20 minutes to get it. It will infect the entire world but China's cases have already peaked. Etc etc.
It's pretty hard for people to know what to make of all this. I'm not saying the information people are getting is wrong, but it sounds contradictory and confusing.
3. If you believe it's really so infectious then there isn't much you can do. Nobody can self-isolate forever, and many can't self-isolate at all.
The real issue with these numbers isn't whether it's larger or a lot larger than regular flu but to what extent any of these numbers are meaningful at all. The same virus supposedly causes death rates of between 0.5% and 5%, an order of magnitude difference. Seems more likely that nobody really knows.
Also, we don't know how many people have been infected. I'm guessing for the flu we have better estimates, as it has been tracked for decades. Besides, "flu" has been a diagnosis commonly used by doctors whenever the symptoms fit. I was told I had a flu by a doctor more than once without any blood tests. So we might have another order of magnitude correction once more data is available.
Yes, it's better be safe than sorry, I get that. However we probably shouldn't use mortality rates as the main reason to panic (or not panic). I shouldn't have done that in my previous comments.