I have one friend who worked at Uber and had years of experience working at another tech company beforehand. Uber basically refused to promote her, even going to far as to hire people significantly junior to her into those senior positions. In one case one of the people who was hired blatantly lied on their resume about their past experience, got caught out for it, and was still hired above her.
Even outside of the bay area Uber has taken many reputation hits for their stupid behavior. The whole incident where they were planning on digging up dirt on a reporter to ruin her character shows a huge lack of ethics at the top of the company. The "god mode" application and research into "one night stands" shows they have no respect for privacy.