It can succeed because your average passenger doesn't know how to determine if the weather is actually bad enough to cancel a flight. They see some clouds out there and take the airline's word for it.
It makes me very happy to see that they have crew problems. After screwing the crew for so long, it was long overdue for the roles to reverse. I also hope this is just the tip of the iceberg.
Ideally the Ryanair crew will follow the pilots from Thomas Cook and go on strike for few days.