There are; they just won't accept any offer. Most of the airline offers I have been offered in this situation were paltry: reschedule and some airline "credit".
Give me a partial or full refund, and I'll be much more willing to volunteer. Otherwise, you're seeing passengers value their time higher than some credit and lost time.
A few people took the offer, I didn't. As a result they denied me boarding and gave me the exact same deal, except it was a $1250 pre-paid credit card. I never expected to be quite so happy about not being allowed on a plane.
They were asking everyone and most people refused. I should have bartered harder to get an upgrade to business.