Uber doesn't get nearly enough good press to outweigh all the negative. Their successes (measured in your standard startup metrics of growth, funding and valuation) all seem pretty petty when the service is seemingly constantly embroiled in some sort of controversy. Whether it's riots and clashes with established taxi companies, serious breaches in privacy that seem to be deeply-rooted at the institutional level, or any number of acts of harrassment or violence by drivers against passengers, there always seems to be something detracting from Uber's all-around brand value.
That they've expanded so aggressively and make such miniscule effort to belay their mistakes is worrisome. Transportation is an industry in need of a major overhaul, but I just don't trust Uber is the right company to do it. It's too bad that they're the only ones out there that seem to be making any large scale impact.