Of course the loss of a single carrier on a route is a negative, to say anything else would be ridiculous. As has been said there are political issues with Cairo and one would hope when things improve there and in Libya we will see the return to services to these countries.
However reading some peoples comments on here you would think we are losing passengers hand over fist, no new services are due and the future of the airport is dire.
There are services coming along that will mitigate these losses, I accept some but maybe not all passengers who used the airlines that have left will move to other carriers from the airport.
More importantly we can hopefully expect the new plans for T1/3 soon which will improve the service from the airport itself. Metrolink is here soon, and long haul services to Hong Kong and hopefully Beijing are very good news for Manchester.
Those who prefer to look at the negatives are free to do so you are wholly entitled to an opinion, but there are some of us who see the positives outweighing the negatives right now.