I think it's all small fry campared to the fuel wasted while holding and being vectored?
All too often a few hundred kg's of fuel is saved on a flight through judicious selection of crusing altitude, speed etc only to arrive and be put in a hold 50nm from destination.
CTA's (controlled times of arrival) are pretty much ignored by most pilots so the controllers just deal with whatever turns up on their screens the best they can.
I have to admit I don't pay much heed to CTA's , I don't see any point when I know most other pilots don't either.
I think that if CTA's were rigidly enforced then a lot of fuel/money could be saved. I think the rule should be that if you aren't within two minutes of your CTA then you hold until a gap opens up or you become fuel critcal. If it was that black and white pilots would know what to expect and could delay departure by a few minutes if a tail wind was forecast, or could call company and give an estimated ETA and recieve a revised CTA for a head wind. I don't think you would end up holding until reserves very often, most of the time a gap would open up pretty quickly but what it means is that the crews who meet their CTA's don't get dicked around, straight on in for them.
What do ya reckon? Am I dream'n?