Which would mean they do _not_ make a profit on each ride.
Charitable interpretation is that the parent is talking about Uber's gross margin, which is presumably fairly high.
randyrand is talking about gross margin; you're thinking about earnings. You can have a positive gross margin and negative earnings. There's no point arguing about whether this does or does not constitute making a profit in some absolute sense - just understand that both are true.
Let's split the difference:
They make profit from some rides. And the amount of profit matters, too.