Well, even if it's only as bad as the flu, what we're talking about is "remember that thing that kills hundreds of thousands every year? We're now going to double that number for the foreseeable future". Unless of course we manage to stop it from spreading further (which seems unlikely at this point but possibly worth trying anyway.)

it's much, much deadlier and more contagious than the flu, there is hardly any research into treatment, no vaccine and no herd immunity. if this gets into serious exponential takeoff, which seems increasingly likely, we're talking about potentially millions of deaths. even if you're at low risk of death, you probably know a few people that aren't.

Because the flu is simply much less lethal than this.