You are not going to Disney or canceling other plans because your afraid of getting the virus......., are you also NOT going to work or out to dinner? Are you not going to the grocery store? are you not going to the post office or bank? are you not going to get gas in your cars? etc...........................
I see your point, but there is a very obvious difference when you expose your self to 1000s (or 10s of 1000s) of people over the course of a few days and encountering a dozen people when home. Also, the odds of encountering people from other parts of the world/country is much higher as well. It's also much simpler to do small things and use proper hygiene habits when you're going out once or twice a day (or week). Traveling in airports/planes alone is a different exposure to germs.
We're planning to go in 10 days unless there's a closure, but the difference in our lives here (where I work from home and spouse works in a very small office) and going to WDW is significant in regard to what we're exposed to.