My decision on traveling to Italy, especially Northern Italy (e.g. Milan and surrounding regions) included my assessment of potential consequence and probability of that happening.
Worst case consequence was the possibility of contracting the COVID-19, being hospitalized in a foreign country and even dying. The likelihood of that is small, very small, but I am of the older demographic. If I had a heart condition, was diabetic and had high blood pressure etc, the risk would be higher. Severe outcome but very low risk.
The less serious consequence would be getting locked in to some town or area by authorities to contain the outbreak, getting quarantined in Italy with the financial cost of room and board, and possibility of a second quarantine back in the States. That probability is unknown but not high. But ask the passengers on the cruise ship in Japan. Moderate outcome and low risk.
The minor impact consequence are closed attractions, canceled events and limited hours on restaurants etc. as Italian authorities are trying to contain the COVID-19. Minimal impact, more of an inconvenience, but a high probability (100% in the case of some Milan attractions). Minor inconvenience with high probability.
With the above in mind, and our event being canceled, we canceled and are trying to recover financially what we can. But to each their own in terms of their assessment of risk and the importance of conferences. Each person is free to make up their own mind until an airline or government authority makes the decision for them.