Why doesn't Ryanair fly on Christmas day?
I had always assumed that airlines which would be left with aircraft in the wrong place if they didn't operate on Christmas Day still operated flights, but otherwise the extra costs of paying staff overtime, combined with the relative lack of demand to travel on this day, meant airlines wouldn't operate.
As it happens, I have been SLF on Christmas day, back in '99, when I flew LHR-BGI with Bewee. The advantage of being somewhere very hot, where the rest of the family already was, meant I accepted the inconvenience - but as there were no trains, we had to drive, then it was cheaper to get a hotel & parking deal, but no shuttle bus so £30 for a taxi. Also, from an operational point of view, cancel a short out & back rotation, there's another flight the next day, if there was no LHR-BGI, there'd be no BGI-LHR the next day.
All that hassle for a European hop? Forget it, I am surprised Easy were operating, especially as they tend to operate higher frequencies than Ryan.