You may think this, but coming from an analogous business I can say virtually all "middlemen" market-making companies (think online travel agents like Booking.com or Expedia) track like this: start at the top with Gross Bookings, then make a bunch of deductions to Net Revenue. And in truth it gives a more accurate picture of the business, because the "Take Rate", that is Net Revenue/Gross Bookings, is an important metric in and of itself.
I think you are confusing the data presented by WSJ with an audited SEC financial report. Uber didn't make anything public - this is just data they presented, privately, to their investors who obviously know the difference. I mean, this data was leaked to WSJ.
