well, it is much better than the previous “fuel per passenger”, withozt considering route length.
Prior metric wasn't included in airline score, thus the unfairness was immaterial to game standings. The new metric is less lopsided than the old one, but it's still fairly significant. It's also inherently flawed as it doesn't consider freight in the calculation, so you're getting fuel burned and no passenger credit there.
Quick comparison in GW3 - Owl Express (SIN - Left) vs Jet Black (ATL - Right)
Total Fleet - 694 vs 567
Revenue Seat Kms - 36,682 vs 31,532
Fuel burn - 439T vs 174T
Fuel per RPK - 145.5 vs 431.9
The statistic actually looks way off from reality, so maybe that'll correct, but regardless, I fly 20% more RPKs than Jet black while burning 2.5x more fuel. I absolutely can't compete in this ranking due to where my demand in SIN is (mostly Europe, 6000nm away).
Maybe you should stick to running a small regional airline then. 
I do what I can