This outbreak just started in earnest weeks ago. It has a 2 week incubation period and the illness may take 1-2 weeks before recovery or death. That's why you must look at dead/recovered. I agree that 53% for the general population is pessimistic because as usual there is a selection bias towards those with weakened immune systems, not by as much as you may think.
As a thought experiment, if you infected an entire city with the flu, the ones to show up at the hospital are the worst cases, and if you just built your data from those people, you'd get a really really skewed perspective.
