Gazwag
5 millionth post poster
When you book and pay for a flight with an airline you have entered into a contract. If they then CHOOSE to cancel this contract because they don't want to fly to that destination any more, they have broken the contract. They took the decision on financial grounds, they should accept responsibility for any loss suffered by their customers.
To follow your logic, you should never plan to do anything based on travel tickets you have bought, since they are essentually worthless in terms of being honoured.
As I said its a risk you take if you dont buy a package holiday. The travel tickets are not worthless though as you will get your money back. Its a case of ensuring you buy good travel insurance.