There has been an explosion of commentary on regulations in Birmingham regarding Uber and its services; I streamed part of yesterday's City Council meeting at which they voted to delay a decision until next week. I wrote an open letter to the Council for Forbes.com and shared it in the r/Birmingham subreddit. A few people asked about the taxi drivers' side of the argument, namely, that they be allowed to compete on a level playing field. People have invoked "safety" as a reason why UberX in particular should face the same regulations as area taxicabs. I think these are interesting issues, but I don't think they make the case for regulation.
If people are really willing to pay a premium for the quality regulation ensures, then unregulated UberX shouldn't threaten regulated and presumably-higher-quality, lower-risk taxis. Riders who want the assurance that they are getting a quality ride will forsake Uber and go with the regulated taxis.
If people aren't willing to pay extra for high quality--if they are willing to accept a bit of additional risk for lower prices--or if Uber's ratings system isn't an effective way to maintain quality, then regulation is at best superfluous and at worst an unnecessary barrier to entry.