Letters have traveled through various postal systems for hundreds of years now. By giving your letter to a postal carrier, you are relinquishing control of it and letting it be processed by a centralized system. Therefore, anyone who sends a private correspondance through a postal system, should have no expectation of privacy. ?
Are network packets really that different? Because technology makes it easier to look at the content of the packet without breaking any wax seals, or having to steam the glue, that makes it ok to look? The 4th amendment protects paper packets, why not electronic packets? The US was founded with personal privacy enshrined as a core principal, so a lot of thick numbskulls like myself carry that expectation across different spectrums.
(Note: In this particular case, I'm not surprised that Uber employees can access Uber data, especially in this example where the reporter called out being late to a meeting with Uber executives while seated in an Uber car)