I'm questioning why they are so severe compared to how we treat influenza.

Perhaps I'm way off base and 50-60% of the country will eventually be infected. However, it is March and this is, I believe, a seasonal virus (like the flu). There are 1300 reported cases in the U.S. at this time and 38 deaths.

It would have to spread awfully quickly to high-risk groups over the next 8 weeks to come close to the number of fatalities we see from influenza.

I don't disagree, finding every possible way to encourage social distancing and quarantining (voluntary and mandated) will reduce the spread. Why don't we do that with the flu? I guess we're okay with 30,000 deaths, so long as we get to attend sporting events.