What a load of Rubbish Compton3bravo..... You say that most passengers got away on other flights from Luton.... That is not true, most flights were jam packed in the days running up to christmas and certainly at the best had a dozen or so seats in the case of easyjet. Why do you think wizzair/aer arran put on extra flights and easyjet increased a/c size on a few departures ?
easyJet cancelled a number of flights one morning as a DIRECT knock on from the disruption events of the previous day with the diversions and delays being experienced causing flight crew out of hours... even a generous amount of standy crew would not be able to cope with the amount of disruption over repeated number of days. Dont forget that a lot of the destination stations in northern and eastern europe were suffering and the cancellations/delays were not purely caused by what was happening in the UK.
When it comes to the amount of money lost.... it runs into a large figure... Just think of all the hotel nights required to accomodate passengers from cancelled flights. under EU law they are legally entitled to a hotel for the entire length of time that they await seats on the next available flight. That maybe one day, it may be fourteen! either way the airline has to pay in the end. Then there will be all the transportation costs of getting passengers to/from diverted aircraft and to/from flights from other airports that had the only available seats to fly on left before christmas. Then add in lost revenue from catering/sales/fees at the airport.... at the busiest time of the winter. I'm not going into commercially sensitive information but it amounts to a considerable amount of money !