1.Airservices now have the National Operations Centre (NOC). They have a wealth of experience and should be able to explain all of this stuff.
Give them a ring and please post some of their answers here. Their 'wealth of experience' will shine through.
As far as ATC (Air Traffic Controllers) go, the guy/girl on the end of the headset has bugger all to do with your problem. In regards to yesterday, we had planes holding up to FL390 with in excess of 40 minute delays at 4 different holding points, when we were advised to issue a Hazard alert for SY for holding up to 60 minutes. I think that horse had bolted by that time. We just get on with it.
Hopefully the US Metron system to absorb the delays on the ground will fix this problem.
As an ATC I share your frustration, we get no joy from more and more aircraft entering the holding patterns to burn more and more fuel. Appreciate that the operational ATC talking to you has bugger all input to these decisions. When we had Operational control, way back when, we would advise pilots that they needed more fuel, now it is basically left up to the companies and the PIC.