My 2 cents is both WN and CO (probably AA also) offered passengers a no penalty reschedule. If I have flexibility in my schedule, I'm not wanting to fly the day a hurricane is coming into town -- and this is spoken from someone who enjoys the some turbulence from time to time, especially if it comes with a light show out my window.

So if they are operating their planes (with far less than normal capacity), then they are losing money. I think WN and AA are wiser for advertising they are canceling the flights and rebooking passengers into available seats on future dates. Now they have the same revenue, but lower costs because they operated less flights. Smart business in my view.