Uber is in for a tough time, its critics agree. The thing is, those critics can't seem to agree about why.

Noting that the San Francisco ride-sharing startup lost somewhere north of $1.2 billion in the first half of 2016, Bloomberg's Justin Fox says that's a problem not because Uber's in danger of running out of money -- it has raised around $15 billion -- but because it spent that money without getting anything concrete in return, on ephemeral stuff like incentives to attract new drivers. These subsidies can't be considered a real investment because it's too easy for drivers and riders alike to switch to rival services, and too easy for competitors to start a rival service since it doesn't require much capital to code a similar app.

Meanwhile, Vanity Fair's Nick Bilton says Uber is in danger because the age of self-driving cars is rapidly approaching. While Uber has invested heavily in autonomous-car technology, and CEO Travis Kalanick has said that's where the company's future lies, the battlefield is arrayed for a clash with big automakers like Ford, Tesla, and Mercedes, which are developing both self-driving technology and car-sharing software of their own.

"[I]f you think about it, Uber isn't actually connecting passengers to cars," writes Bilton. "Instead, it is really connecting passengers to drivers. When those drivers are replaced by computers, Uber is a less important, and less valuable, middle man."

Is that so, though? After all, someone has to be that middle man, even if that someone is no one. That's because self-driving won't just affect who operates cars but who owns them, as Bilton himself notes. "With the exception of the 0.001 percent, it's unlikely that most of us will actually own a car," he writes. "Rather, we will probably subscribe to them, or essentially rent their usage, in the same way that we currently consume digital books or music or movies, which we enjoy in our living rooms but technically live in a far-off digital cloud."

That's an instructive example because publishers and entertainment conglomerates for years have tried to claim what they see as their rightful share of the digital-content-rentals business, but most of their efforts have been failures, while tech "middle men" like Amazon, Netflix, Apple, and Spotify have flourished. Why should it be any different for carmakers?

If anything, it's likely to be even more difficult for them. Automakers are good at two things: manufacturing cars and branding themselves so they can sell the cars they make at a nice margin. With rare exceptions, like Tesla, they don't even handle the sales themselves. Those competencies will be 99 percent irrelevant in the self-driving, post-ownership future Bilton foresees. A person who needs to get from home to work doesn't care if he gets there in a BMW or a Volvo any more than you care whether Boeing or Airbus makes the jumbo jet you fly in. That's why Boeing and Airbus don't have their own airlines. For the big automakers to prevail in the future, they'd have to radically reinvent themselves as service companies, something they're entirely unequipped to do (as Stratechery's Ben Thompson notes).

Uber is already a service company. All it has to do to be competitive in the self-driving world is acquire a fleet of cars, or partner with someone willing to handle that side of things. (Perhaps Tesla, as Recode's Johana Bhuiyan suggests.) Service companies throughout history have fared just fine while owning some physical infrastructure; it's only in the past few years that that arrangement has come to seem like a weakness. In fact, by investing in its own fleet, Uber will have done exactly the thing Justin Fox knocks it for not doing now: spending its billions on something that represents a meaningful defensive moat to would-be competitors.

Not all would-be competitors, perhaps. There are still the tech companies to worry about; Apple, Google, and even Amazon all have expertise in hardware manufacturing, software, and services. If anyone's going to snatch the future out from under Uber's nose, it will be one of those players -- not a carmaker desperately trying to avoid extinction.