Well, because whomever's in charge of such surcharge matters, has shown a consistent approach recently to screwing the pax for the most money basically. In fact I have no doubt that they sit down in mgmt. or board meetings regularily to determine where next to levy another charge, or raise prices without impacting on their advertised sale fares.
Then they go off and give sale fares for £50 return to LUX , VNO & Thessalonika....would rather they just chilled out a bit & made everything reasonable.
But you get a fully catered flight now don't you, and should be grateful.
Besides which, we all fly F & don't care.