It's easy to say that they should just ride whatever the course is, but putting a 3 hour transfer immediately before a 260km stage and the day after a huge climbing day is excessive.
Adam Hansen tweeted that rider representatives met with the organiser the night before, who refused to change the stage at all. These guys take huge risks on their bikes the whole time and treat it like it's nothing, so when they collectively agree not to race because they feel it's too much of a health risk, I tend to think they should be listened to.
That's not to deny the upset of the volunteers, the townspeople, and whoever was missed out of the race, just that fundamentally they aren't the ones putting their necks on the line.