I agree with all the views expressed by the posters before me.
I would question what role United has played in this mess. I am not questioning the crew or the poor customer services agent at SFO.
Did United accept the bookings from the cruise-line company without informing the crew and customer services folks?
Perhaps it is the sales department at United not doing enough due diligence or planning before accepting the bookings/
IF the bookings were made in advance of the outbreak, United should aggressively monitor the situation and how it could impact the safety of its crews and staff.
I am with the crew who refuse to fly, and United should not put its employees in this situation in the first place.