I wanted to stay out of this hoping someone would explain the rationale , but since no one did so far , let me have a go.
The “ good old days” are slowly going away and in today and future ATM world the “ client” of ATC is no longer the pilots , but the Airlines , the “ Operators” as Eurocontrol call them .
What hurts the Airlines today are the delays ( or so they hammered Eurocontrol and the FAA ) and they apply pressure for ATM to be more efficient and cheaper. The answer is developing capacity to eliminate delay and allow airlines to fly their preferred requested profiles. For maximizing en-route capacity , flight plan adherence is the key . And there you get what Gonzo posted earlier.
Just 2 quotes from that plan :
Use of DCT, while often desirable, can be the cause of sector
overloads, approach sequencing problems and timing issues
for ground handling.
“The operator shall ensure prior to operation of the flight that
the content of the initial flight plan correctly reflects the operational
intentions.”
ATC ( i.e. the controllers) should do their best to accommodate the requests of the Airlines which now makes the FPL. In many Airlines the pilots have little choice in the FPL made . The problem comes when the flight ( i.e. the pilot on board ) asked for something else ( a direct or a different FL than the RFL) That comes mostly from the belief that the Airline flight plan is just a vague idea of what was needed to get the aircraft airborne on time, and that once in the air , the pilots can get back to direct and optimum FL as they would have filed themselves, as before.
I believe we are in transition phase, where pilots and controllers in today environment are caught between the old need to “ expedite” and the need to give the best service , and the current ATM “ global economic ” view . Slowly but surely the game becomes economic and no longer operational. If it is cheaper for your airline to fly 100 NM more to avoid X country high route charges, and if filing a lower than optimum FL gets you going ½ hour earlier , your airline might choose those options.
So there is no point getting at the other group about who is there for who and if RFL or DCT is a right or a favor. . We both Pilots and controllers have to adapt to a growing economic area where economics are slowly taking over old operational considerations.
Last one about Spain and "the good old days" : For those of you who remember Spantax and the Old under-Franco military-ATC in Falty towers-English done in that time over Spain, Flying there today is a paradise.