I have to admit I hadn't noticed the number of KLM cancellations recently and fully understand why passengers are frustrated. However, without sounding too defensive of the airline because I have no links with them, aircraft do suffer from technical problems which cannot always been foreseen.
I agree with Bristol Traveller in that I would be annoyed if my plans were ruined but if there is a technical problem I would rather not get on the aircraft.
The airline I work for has never to this day cancelled a flight on the day of departure due to passenger numbers. I cannot say this will not happen with other carriers especially in the current climate and it would be worth contacting the CAA, as they can locate the exact cause from the carrier. If it is the commercial cancellation on the day you are entitled to compensation which whilst it wont get your day back, may contribute towards any other flight ticket you have to purchase to get to your destination.
Out of curiosity EasyJet dont operate to Amsterdam from BRS do they?