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Josh Mohrer, Uber’s General Manager for New York City, created a hostile culture. Mike Isaac’s Super Pumped (p. 169) explains:

Mohrer leaned hard on his people–browbeating them when he needed to–never accepting excuses. … Mohrer would pit his employees against each other to see who could impress him or deliver better–a tactic espoused by Kalanick himself.  Subtle intimidation of his underlings sometimes meant flicking at their flaws, like inspecting the receding hairline of an employee as they tried to discuss a project with their boss.  He described the shortcoming of an individual employee in front of the entire office, praising winners and shaming losers. … [A]round the office, according to two employees, he seemed like a shorter version of Biff Tannen, the high school bully antagonist from Back to the Future.

But Isaac reports that Uber ignored any concerns about culture:

Mohrer always hit his numbers, no matter what.  And that was what mattered at Uber. His business success kept Mohrer’s position secure at the company for years.

Isaac reports (p. 323) that Mohrer was ultimately fired as part of the Holder report.

Mike Isaac’s Super Pumped (p. 169) reports Uber’s “champion’s mindset” of “Kill or be killed.”  Isaac explains:

[I]f you weren’t watching your back you might be betrayed by a colleague looking to get ahead.  Success, many believed, only came at the expense of others.

Isaac continues (p. 267) that an employee “recalled a director boasting about withholding information from one executive to curry favor with another (and it worked.”  His conclusion: “Backstabbing was not only endorsed, but encouraged.”