Reason for cancelling early is to avoid having planes spread/dumped all over Europe due to airports being closed and diverting. If the 1st wave left early this morning they would not be able to land back in LGW causing even further problems for themselves and the passengers. At least now they know that the whole fleet is waiting in LGW ready to fly the next bunch of passengers away to their destinations.
A very complex job having crew sent by taxis/busses across Europe when airports are closed.
A lesson that was learnt during the volcanic ash clouds where ops wanted the planes going knowing they couldn't fly back etc. Causing themselves a big headache loosing track of what airplane was at what airport and so on.
Hope it makes sense to the normal passenger.
Ps. LGW base have 42 planes for this winter (43 this summer) and with the just newly announced routes we will have 46 for summer 2011.