I read an article talking about how viruses change as they hop from animal to human, and when they do so they are "young" from a human standpoint. It took an evolution to make such a leap, and viral evolution is not uncommon, which is why we have so many flus and not 1 true vaccine, for example. As a virus' main concern is to replicate and pass to a new host, it is not advantageous to be lethal prior to transmission. Our immune system is different of that of birds and bats so the virus must mutate to use us effectively as hosts, and most importantly, those mutations are not necessarily bad for us as its an automatic compromise between the virus and our immune system.
His point? Sort of the opposite of your last line, and keep in mind 2 things: we can't really trust the numbers out of China, and we probably can trust the numbers out of Italy, but they have an aging population that is exactly who this virus thrives in.
No source, can't remember where I read it.