It all depends on what you want F1 to be. It already has spec tires and spec electronics, so why not spec fuel?
In my mind, the sport has already gone too far down the road toward uniform specifications which inhibit creative thinking but I know others disagree. So let me ask you this:
If there is to be spec fuel and spec tires, shouldn't there also be spec engines? How about spec transmissions, turbos, ERS, etc? Or spec drivers?
And hey, if we are going to go that far, why not eliminate those pesky drivers all together and let Google sort it all out with a fleet of autonomous cars on track?
OK, that last may be hyberbole.
My point is, when one team or one driver runs away with the championship, we all yak about changing the rules to make the racing closer. When the racing gets closer, we all yak about how the rules prevent innovation.
So before we start introducing spec fuel, maybe the first question that needs to be answered is "What do you want Formula One to be?
That should take up several gig of server space!